Piano
Salamander Grand Piano (Yamaha C5) by Alexander Holm, licensed CC BY 3.0. Trimmed and re-encoded to MP3 for the web.
Electric piano, pad, strings, organ, guitar, vibraphone, synth lead, basses
FluidR3 GM soundfont by Frank Wen, licensed CC BY 3.0, rendered to MP3 by Benjamin Gleitzman's midi-js-soundfonts. Trimmed and re-encoded.
Drums
Versilian Community Sample Library by Versilian Studios, released CC0. The electro kick is synthesized.