cadence is a free music bot for Discord.

It is written in Typescript, NodeJS, and powered by Lavalink (https://github.com/freyacodes/Lavalink).

Features:

• Play music in your Discord server given a url or keywords.
• Based on Youtube videos.
• Supports Spotify links (tracks, playlists), will try its best to find the Youtube version.
• Fancy player controller based on buttons (pause, play next/prev, loop, stop).
• No duration limit, can play 24/7.
• Can be self-hosted [1].

[1] = Self-hosted is basically allowed (docker image is even published on hub.docker.com to ddries/cadence), but you'll have to play with the source code to identify config params.