diff --git a/.gitignore b/.gitignore
index 47042c2..fd01f05 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
+.build
+.swiftpm
 .DS_Store
 xcuserdata
diff --git a/MusicKit.xcodeproj/project.pbxproj b/MusicKit.xcodeproj/project.pbxproj
index 7a24b08..23f2922 100644
--- a/MusicKit.xcodeproj/project.pbxproj
+++ b/MusicKit.xcodeproj/project.pbxproj
@@ -133,7 +133,7 @@
 		965AF8C11AF7A1DA00D31E83 /* Protocols.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Protocols.swift; sourceTree = "<group>"; };
 		9662BFF01B058568008A053A /* IntervalQuality.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = IntervalQuality.swift; sourceTree = "<group>"; };
 		96686DB41A573B7F00350A2D /* PitchTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PitchTests.swift; sourceTree = "<group>"; };
-		966E60FA1B0930E9005EE226 /* AlteredPentads.playground */ = {isa = PBXFileReference; lastKnownFileType = file.playground; name = AlteredPentads.playground; path = ../Playgrounds/AlteredPentads.playground; sourceTree = "<group>"; };
+		966E60FA1B0930E9005EE226 /* AlteredPentads.playground */ = {isa = PBXFileReference; lastKnownFileType = file.playground; name = AlteredPentads.playground; path = ../Playgrounds/AlteredPentads.playground; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.swift; };
 		967070E81B0850AC00CB367E /* ChordExtensions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ChordExtensions.swift; sourceTree = "<group>"; };
 		967070EB1B08512A00CB367E /* ChordQualities.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ChordQualities.swift; sourceTree = "<group>"; };
 		967070EE1B08649200CB367E /* ChordQualityTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ChordQualityTests.swift; sourceTree = "<group>"; };
@@ -536,6 +536,7 @@
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
 			knownRegions = (
+				English,
 				en,
 			);
 			mainGroup = 96F299181A5663E500D7B006;
@@ -716,10 +717,6 @@
 		9691BB2E1A57C75500421B56 /* Debug */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				FRAMEWORK_SEARCH_PATHS = (
-					"$(SDKROOT)/Developer/Library/Frameworks",
-					"$(inherited)",
-				);
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"DEBUG=1",
 					"$(inherited)",
@@ -730,24 +727,20 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "benzguo.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
 		9691BB2F1A57C75500421B56 /* Release */ = {
 			isa = XCBuildConfiguration;
 			buildSettings = {
-				FRAMEWORK_SEARCH_PATHS = (
-					"$(SDKROOT)/Developer/Library/Frameworks",
-					"$(inherited)",
-				);
 				INFOPLIST_FILE = MusicKitTests/Info.plist;
 				IPHONEOS_DEPLOYMENT_TARGET = 8.1;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "benzguo.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 				VALIDATE_PRODUCT = YES;
 			};
 			name = Release;
@@ -765,7 +758,6 @@
 					"$(inherited)",
 				);
 				INFOPLIST_FILE = MusicKit/Info.plist;
-				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.1;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "benzguo.$(PRODUCT_NAME:rfc1034identifier)";
@@ -773,7 +765,7 @@
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = "";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -787,7 +779,6 @@
 				DYLIB_CURRENT_VERSION = 1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INFOPLIST_FILE = MusicKit/Info.plist;
-				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 8.1;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "benzguo.$(PRODUCT_NAME:rfc1034identifier)";
@@ -795,7 +786,7 @@
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = "";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 			};
@@ -901,6 +892,7 @@
 				SKIP_INSTALL = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -921,6 +913,7 @@
 				PRODUCT_NAME = MusicKit;
 				SKIP_INSTALL = YES;
 				SWIFT_OBJC_BRIDGING_HEADER = "";
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
@@ -940,6 +933,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "benzguo.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -955,6 +949,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "benzguo.$(PRODUCT_NAME:rfc1034identifier)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};
diff --git a/MusicKit.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/MusicKit.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 0000000..18d9810
--- /dev/null
+++ b/MusicKit.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/MusicKit.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/MusicKit.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 0000000..18d9810
--- /dev/null
+++ b/MusicKit.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/MusicKit/ChordQualities.swift b/MusicKit/ChordQualities.swift
index 4eb1e5d..1741bdf 100644
--- a/MusicKit/ChordQualities.swift
+++ b/MusicKit/ChordQualities.swift
@@ -1,10 +1,10 @@
 import Foundation
 
 public extension ChordQuality {
-public static let Dyads = [
+static let Dyads = [
 ChordQuality.PowerChord,
 ]
-public static let Triads = [
+static let Triads = [
 ChordQuality.Major,
 ChordQuality.Minor,
 ChordQuality.Augmented,
@@ -12,7 +12,7 @@ ChordQuality.Diminished,
 ChordQuality.Sus2,
 ChordQuality.Sus4,
 ]
-public static let UnalteredTetrads = [
+static let UnalteredTetrads = [
 ChordQuality.DominantSeventh,
 ChordQuality.MajorSeventh,
 ChordQuality.MinorMajorSeventh,
@@ -22,7 +22,7 @@ ChordQuality.AugmentedSeventh,
 ChordQuality.HalfDiminishedSeventh,
 ChordQuality.DiminishedSeventh,
 ]
-public static let AlteredTetrads = [
+static let AlteredTetrads = [
 ChordQuality.DominantSeventhFlatFive,
 ChordQuality.MajorSeventhFlatFive,
 ChordQuality.DominantSeventhSusFour,
@@ -39,7 +39,7 @@ ChordQuality.AddSharpEleven,
 ChordQuality.MinorAddSharpEleven,
 ChordQuality.AugmentedAddSharpEleven,
 ]
-public static let UnalteredPentads = [
+static let UnalteredPentads = [
 ChordQuality.DominantNinth,
 ChordQuality.MajorNinth,
 ChordQuality.MinorMajorNinth,
@@ -49,7 +49,7 @@ ChordQuality.AugmentedNinth,
 ChordQuality.HalfDiminishedNinth,
 ChordQuality.DiminishedNinth,
 ]
-public static let AlteredPentads = [
+static let AlteredPentads = [
 ChordQuality.DominantSeventhFlatNine,
 ChordQuality.MajorSeventhFlatNine,
 ChordQuality.MinorMajorSeventhFlatNine,
@@ -73,7 +73,7 @@ ChordQuality.DiminishedSeventhFlatThirteen,
 ChordQuality.Dominant9Sus4,
 ChordQuality.SixNine,
 ]
-public static let UnalteredHexads = [
+static let UnalteredHexads = [
 ChordQuality.DominantEleventh,
 ChordQuality.MajorEleventh,
 ChordQuality.MinorMajorEleventh,
@@ -83,7 +83,7 @@ ChordQuality.AugmentedEleventh,
 ChordQuality.HalfDiminishedEleventh,
 ChordQuality.DiminishedEleventh,
 ]
-public static let AlteredHexads = [
+static let AlteredHexads = [
 ChordQuality.DominantEleventhFlatNine,
 ChordQuality.MajorEleventhFlatNine,
 ChordQuality.MinorMajorEleventhFlatNine,
@@ -121,7 +121,7 @@ ChordQuality.MajorSeventhSharpElevenFlatThirteen,
 ChordQuality.MinorMajorSeventhSharpElevenFlatThirteen,
 ChordQuality.MinorSeventhSharpElevenFlatThirteen,
 ]
-public static let UnalteredHeptads = [
+static let UnalteredHeptads = [
 ChordQuality.DominantThirteenth,
 ChordQuality.MajorThirteenth,
 ChordQuality.MinorMajorThirteenth,
@@ -131,7 +131,7 @@ ChordQuality.AugmentedThirteenth,
 ChordQuality.HalfDiminishedThirteenth,
 ChordQuality.DiminishedThirteenth,
 ]
-public static let AlteredHeptads = [
+static let AlteredHeptads = [
 ChordQuality.DominantThirteenthFlatNine,
 ChordQuality.MajorThirteenthFlatNine,
 ChordQuality.MinorMajorThirteenthFlatNine,
@@ -173,11 +173,11 @@ ChordQuality.MajorSeventhFlatNineSharpElevenFlatThirteen,
 ChordQuality.MinorMajorSeventhFlatNineSharpElevenFlatThirteen,
 ChordQuality.MinorSeventhFlatNineSharpElevenFlatThirteen,
 ]
-public static let Tetrads = ChordQuality.UnalteredTetrads + ChordQuality.AlteredTetrads
-public static let Pentads = ChordQuality.UnalteredPentads + ChordQuality.AlteredPentads
-public static let Hexads = ChordQuality.UnalteredHexads + ChordQuality.AlteredHexads
-public static let Heptads = ChordQuality.UnalteredHeptads + ChordQuality.AlteredHeptads
-public static let All = [
+static let Tetrads = ChordQuality.UnalteredTetrads + ChordQuality.AlteredTetrads
+static let Pentads = ChordQuality.UnalteredPentads + ChordQuality.AlteredPentads
+static let Hexads = ChordQuality.UnalteredHexads + ChordQuality.AlteredHexads
+static let Heptads = ChordQuality.UnalteredHeptads + ChordQuality.AlteredHeptads
+static let All = [
 ChordQuality.PowerChord,
 ChordQuality.Major,
 ChordQuality.Minor,
@@ -331,7 +331,7 @@ ChordQuality.MajorSeventhFlatNineSharpElevenFlatThirteen,
 ChordQuality.MinorMajorSeventhFlatNineSharpElevenFlatThirteen,
 ChordQuality.MinorSeventhFlatNineSharpElevenFlatThirteen,
 ]
-public var name: String {
+var name: String {
 switch self {
 case .PowerChord: return "PowerChord"
 case .Major: return "Major"
diff --git a/MusicKit/MIDI.swift b/MusicKit/MIDI.swift
index bc62f82..70e0469 100644
--- a/MusicKit/MIDI.swift
+++ b/MusicKit/MIDI.swift
@@ -2,6 +2,10 @@
 
 import Foundation
 import CoreMIDI
+#if SWIFT_PACKAGE
+import MKMIDIProc
+#endif
+
 
 open class MIDI {
     /// Messages sent to the virtual MIDI source will be delivered on this channel.
@@ -63,11 +67,11 @@ open class MIDI {
         let s = MIDIReceived(_virtualSource, packetList)
         success = s == 0
 
-        packet.deinitialize()
+        packet.deinitialize(count: MemoryLayout<MIDIPacket>.size)
         // this dealloc is superfluous; not sure why.
 //        packet.dealloc(sizeof(MIDIPacket))
-        packetList.deinitialize()
-        packetList.deallocate(capacity: MemoryLayout<MIDIPacketList>.size)
+        packetList.deinitialize(count: MemoryLayout<MIDIPacket>.size)
+        packetList.deallocate()
         return success
     }
 
diff --git a/MusicKit/MIDIMessage.swift b/MusicKit/MIDIMessage.swift
index b0a6a3f..2ad861c 100644
--- a/MusicKit/MIDIMessage.swift
+++ b/MusicKit/MIDIMessage.swift
@@ -1,6 +1,9 @@
 //  Copyright (c) 2015 Ben Guo. All rights reserved.
 
 import Foundation
+#if SWIFT_PACKAGE
+import MKMIDIProc
+#endif
 
 public protocol MIDIMessage {
     /// The message's channel
diff --git a/MusicKit/Pitch.swift b/MusicKit/Pitch.swift
index 298eee6..3311b65 100644
--- a/MusicKit/Pitch.swift
+++ b/MusicKit/Pitch.swift
@@ -80,8 +80,8 @@ extension Pitch: CustomStringConvertible {
 
 // MARK: Hashable
 extension Pitch: Hashable {
-    public var hashValue: Int {
-        return midi.hashValue
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(midi)
     }
 }
 
diff --git a/MusicKit/Temperament.swift b/MusicKit/Temperament.swift
index fd06f8c..e21bbfb 100644
--- a/MusicKit/Temperament.swift
+++ b/MusicKit/Temperament.swift
@@ -6,6 +6,8 @@
 //  Copyright © 2017 benzguo. All rights reserved.
 //
 
+import Darwin
+
 public struct Temperament: Equatable, Hashable {
     
     public static let just = Temperament([1.0000, 1.0417, 1.1250, 1.2000,
@@ -82,15 +84,13 @@ public struct Temperament: Equatable, Hashable {
         return lhs.ratios == rhs.ratios
     }
     
-    public var hashValue: Int {
+    public func hash(into hasher: inout Hasher) {
         if let ratio = ratios.first {
-            return ratios.dropFirst().reduce(ratio.hashValue, {
-                sum, value in
-                return sum ^ value.hashValue
+            hasher.combine(ratio)
+            ratios.dropFirst().forEach({
+                value in
+                hasher.combine(value)
             })
         }
-        else {
-            return 0
-        }
     }
 }
diff --git a/MusicKit/Translation.swift b/MusicKit/Translation.swift
index ed2de88..02456ae 100644
--- a/MusicKit/Translation.swift
+++ b/MusicKit/Translation.swift
@@ -79,7 +79,9 @@ extension Translation:Equatable, Hashable {
                lhs.numerals == rhs.numerals &&
                lhs.showNatural == rhs.showNatural
     }
-    public var hashValue: Int {
-        return self.language.hashValue ^ self.numerals.hashValue ^ self.showNatural.hashValue
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(self.language)
+        hasher.combine(self.numerals)
+        hasher.combine(self.showNatural)
     }
 }
diff --git a/MusicKit/include/headers.h b/MusicKit/include/headers.h
new file mode 100644
index 0000000..578f414
--- /dev/null
+++ b/MusicKit/include/headers.h
@@ -0,0 +1 @@
+#import "../MusicKit.h"
diff --git a/MusicKitTests/ChordNameBasicTests.swift b/MusicKitTests/ChordNameBasicTests.swift
index 2292468..54a3490 100644
--- a/MusicKitTests/ChordNameBasicTests.swift
+++ b/MusicKitTests/ChordNameBasicTests.swift
@@ -6,124 +6,124 @@ final class ChordNameBasicTests: XCTestCase {
         let sut: PitchSet = [Chroma.c*0, Chroma.g*0, Chroma.c*2]
         let name = Chord.name(sut)
         let expected = "C5"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testMajorMinor() {
         var sut: PitchSet = [Chroma.c*0, Chroma.e*2, Chroma.g*3, Chroma.c*4]
         var name = Chord.name(sut)
         var expected = "CM"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.e*2, Chroma.g*3, Chroma.c*4, Chroma.g*4]
         name = Chord.name(sut)
         expected = "CM/E"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.g*0, Chroma.ds*2, Chroma.g*3, Chroma.c*4, Chroma.g*4]
         name = Chord.name(sut)
         expected = "Cm/G"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testOtherTriads() {
         var sut: PitchSet = [Chroma.c*0, Chroma.e*2, Chroma.gs*3, Chroma.c*4]
         var name = Chord.name(sut)
         var expected = "C+"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.ds*2, Chroma.fs*3, Chroma.c*4, Chroma.fs*4]
         name = Chord.name(sut)
         expected = "C°/E♭"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.g*2, Chroma.d*3, Chroma.c*4, Chroma.g*4]
         name = Chord.name(sut)
         expected = "Gsus4"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.c*2, Chroma.f*3, Chroma.c*4, Chroma.g*4]
         name = Chord.name(sut)
         expected = "Csus4"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.c*2, Chroma.d*3, Chroma.c*4, Chroma.g*4]
         name = Chord.name(sut)
         expected = "Csus2"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testCommonTetrads() {
         var sut: PitchSet = [Chroma.c*0, Chroma.e*2, Chroma.g*3, Chroma.as*4, Chroma.g*3]
         var name = Chord.name(sut)
         var expected = "C7"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.g*0, Chroma.ds*2, Chroma.c*3, Chroma.as*4, Chroma.g*3]
         name = Chord.name(sut)
         expected = "Cm7/G"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.b*0, Chroma.g*2, Chroma.d*3, Chroma.fs*4, Chroma.g*3]
         name = Chord.name(sut)
         expected = "GΔ7/B"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.b*0, Chroma.d*2, Chroma.f*3, Chroma.gs*4, Chroma.d*3]
         name = Chord.name(sut)
         expected = "B°7"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testOtherTetrads() {
         var sut: PitchSet = [Chroma.c*0, Chroma.ds*2, Chroma.g*3, Chroma.b*4, Chroma.g*3]
         var name = Chord.name(sut)
         var expected = "CmΔ7"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.e*0, Chroma.c*2, Chroma.gs*3, Chroma.b*4, Chroma.gs*3]
         name = Chord.name(sut)
         expected = "C+Δ7/E"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.b*0, Chroma.g*2, Chroma.ds*3, Chroma.f*4, Chroma.g*3]
         name = Chord.name(sut)
         expected = "B+add♯11"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.b*0, Chroma.d*2, Chroma.f*3, Chroma.a*4, Chroma.d*3]
         name = Chord.name(sut)
         expected = "Bø7"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.b*0, Chroma.cs*2, Chroma.f*3, Chroma.g*4, Chroma.cs*3]
         name = Chord.name(sut)
         expected = "G7♭5/B"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.c*0, Chroma.e*2, Chroma.fs*3, Chroma.b*4, Chroma.c*3]
         name = Chord.name(sut)
         expected = "Esus2/C"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.c*0, Chroma.g*2, Chroma.f*3, Chroma.as*4, Chroma.c*3]
         name = Chord.name(sut)
         expected = "C7sus4"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.g*0, Chroma.g*2, Chroma.f*3, Chroma.b*4, Chroma.c*3]
         name = Chord.name(sut)
         expected = "CΔ7sus4/G"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.g*0, Chroma.d*2, Chroma.b*3, Chroma.e*4, Chroma.g*3]
         name = Chord.name(sut)
         expected = "G6"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.g*0, Chroma.d*2, Chroma.as*3, Chroma.e*4, Chroma.g*3]
         name = Chord.name(sut)
         expected = "Gm6"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 }
diff --git a/MusicKitTests/ChordNameExtendedTests.swift b/MusicKitTests/ChordNameExtendedTests.swift
index c4fe11b..55b8999 100644
--- a/MusicKitTests/ChordNameExtendedTests.swift
+++ b/MusicKitTests/ChordNameExtendedTests.swift
@@ -6,44 +6,48 @@ final class ChordNameExtendedTests: XCTestCase {
         var sut: PitchSet = [Chroma.cs*0, Chroma.e*2, Chroma.g*3, Chroma.c*4]
         var name = Chord.name(sut)
         var expected = "CM/C♯"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.fs*0, Chroma.ds*2, Chroma.g*3, Chroma.c*4]
         name = Chord.name(sut)
         expected = "Cm/F♯"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testPentads() {
         let sut: PitchSet = [Chroma.as*0, Chroma.cs*1, Chroma.e*1, Chroma.g*1, Chroma.c*2]
         let name = Chord.name(sut)
         let expected = "B♭°9"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testSlashPentads() {
         var sut: PitchSet = [Chroma.cs*0, Chroma.as*1, Chroma.e*2, Chroma.g*3, Chroma.c*4]
         var name = Chord.name(sut)
         var expected = "C7/C♯"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
 
         sut = [Chroma.e*0, Chroma.as*1, Chroma.ds*2, Chroma.g*3, Chroma.c*4]
         name = Chord.name(sut)
         expected = "Cm7/E"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testHexads() {
         let sut: PitchSet = [Chroma.c*0, Chroma.e*0, Chroma.gs*0, Chroma.b*0, Chroma.d*1, Chroma.f*1]
         let name = Chord.name(sut)
         let expected = "C+Δ11"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 
     func testHeptads() {
-        let sut: PitchSet = [Chroma.c*0, Chroma.e*0, Chroma.g*0, Chroma.as*0, Chroma.d*1, Chroma.f*1, Chroma.gs*1]
+        let sut = PitchSet([
+            Chroma.c*0, Chroma.e*0, Chroma.g*0,
+            Chroma.as*0, Chroma.d*1, Chroma.f*1,
+            Chroma.gs*1
+        ])
         let name = Chord.name(sut)
         let expected = "C11♭13"
-        XCTAssert(name == expected, "\(name) != \(expected)")
+        XCTAssert(name == expected, "\(name ?? "") != \(expected)")
     }
 }
diff --git a/MusicKitTests/ScaleTests.swift b/MusicKitTests/ScaleTests.swift
index 51ff3c5..f33ac25 100644
--- a/MusicKitTests/ScaleTests.swift
+++ b/MusicKitTests/ScaleTests.swift
@@ -4,7 +4,7 @@ import MusicKit
 final class ScaleTests: XCTestCase {
     func testMajor() {
         let sut = Scale.Major(Chroma.c*5)
-        let expected: PitchSet = [
+        let expected = PitchSet([
             Chroma.c*5,
             Chroma.d*5,
             Chroma.e*5,
@@ -12,13 +12,13 @@ final class ScaleTests: XCTestCase {
             Chroma.g*5,
             Chroma.a*5,
             Chroma.b*5,
-        ]
+        ])
         XCTAssertEqual(sut, expected)
     }
 
     func testPhrygian() {
         let sut = Scale.Phrygian(Chroma.e*5)
-        let expected: PitchSet = [
+        let expected = PitchSet([
             Chroma.e*5,
             Chroma.f*5,
             Chroma.g*5,
@@ -26,15 +26,15 @@ final class ScaleTests: XCTestCase {
             Chroma.b*5,
             Chroma.c*6,
             Chroma.d*6,
-        ]
+        ])
         XCTAssertEqual(sut, expected)
     }
 
     func testChromatic() {
         let sut = Scale.Chromatic(Chroma.c*5)
-        let chromatic: PitchSet = [Chroma.c*5, Chroma.cs*5, Chroma.d*5,
+        let chromatic = PitchSet([Chroma.c*5, Chroma.cs*5, Chroma.d*5,
             Chroma.ds*5, Chroma.e*5, Chroma.f*5, Chroma.fs*5, Chroma.g*5,
-            Chroma.gs*5, Chroma.a*5, Chroma.as*5, Chroma.b*5]
+            Chroma.gs*5, Chroma.a*5, Chroma.as*5, Chroma.b*5])
         XCTAssertEqual(sut, chromatic)
     }
 }
diff --git a/Package.swift b/Package.swift
new file mode 100644
index 0000000..8e6c50c
--- /dev/null
+++ b/Package.swift
@@ -0,0 +1,41 @@
+// swift-tools-version:5.1
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "MusicKit",
+    products: [
+        .library(
+            name: "MusicKit",
+            targets: ["MusicKit"]),
+    ],
+    dependencies: [],
+    targets: [
+        .target(
+            name: "MKMIDIProc",
+            path: "MusicKit",
+            sources: [
+                "MKMIDIProc.h",
+                "MKMIDIProc.m"
+            ]
+        ),
+        .target(
+            name: "MusicKit",
+            dependencies: [
+                .target(name: "MKMIDIProc")
+            ],
+            path: "MusicKit",
+            exclude: [
+                "MKMIDIProc.h",
+                "MKMIDIProc.m"
+            ]
+        ),
+        .testTarget(
+            name: "MusicKitTests",
+            dependencies: ["MusicKit"],
+            path: "MusicKitTests"
+        ),
+    ]
+)
+