If you are looking for open-source sampled instruments to use in your music, here's a great repository:
https://sfzinstruments.github.io/

They use the SFZ format which is the best way to make sampled instruments. It's open-source, easy to edit (all based on text + audio files) and well documented.

To use these instruments in Ardour or other DAWs I'd recommend the open-source plug-in sfizz:

https://sfz.tools/sfizz/

More about the SFZ format here:
https://sfzformat.com/

#MusicProduction #FOSS