I'll leave that up to others to suggest. There's many Gnutella programs to choose from. But learning how to pick good from bad quality music is a skill you should learn. There are many tips on these forums, sometimes limited to specific forum sections, but the principles are the same for all the gnutella programs, and if you wish to learn about them, worth searching unless someone wishes to suggest them. Here's one example where to find them. eg: How to find music, & Typical file SIZEs of Spammed Virus files posing as audio files.

I'd recommend two sources of music. (1) with due care using a gnutella program, using hopefully new learnt skills to find decent quality audio files. (2) using a genuine Torrent program, either uTorrent or Vuse (Azureus).