I can't help you explore more bluegrass, but I do have some other recommendations. I was hoping no one would mention Mr. Bungle's California (definitely available through iTunes, though I can't give you a link); you seem like someone who would really like it. Off that album, the best songs to sample are "Ars Moriendi" and "Goodbye Sober Day". The album is an incredible mix of styles, and both these songs showcase that variety and lead singer Mike Patton's amazingly flexible voice.

For plainer, but still well-crafted fare, I suggest (again repeating someone else) The Arcade Fire's Funeral. The track "Neighborhood #3 (Power Out)" may be the best to start with, but once you grow to like this album, it's very hard to pick a best track.

If you like (or are intrigued by the idea of) epic, orchestral rock, I can suggest Explosions in the Sky in addition to the more ambient Godspeed! You Black Emperor. Both these bands fall under the heading of "post-rock". Any Explosions album is good, but I'd check out The Earth Is Not a Cold Dark Place. Post-rock thrives on long songs and continuous albums, so just start from the beginning and keep listening.

You can listen to the rest of the albums I mention in their entirety on Warp Records's bleep.com.

Prefuse 73's work is a perfect blend of hip-hop and electronic production, with some soulful barrio flair thrown in as well. I like his earlier work best of all, but his new album, Surrounded by Silence, is also great. I think the song "We Got Our Own Way", which features vocals from Blonde Redhead's lead singer, Kazu, is utterly beautiful.

If you want to get a little more out there in the electronic field, check out Merck Records's superstar Travis Stewart in his alter egos Machine Drum and Syndrone; his albums Now You Know and Triskaideka, though still somewhat grounded in a hip-hop mentality, are the work of a master electronic beatsmith. This is some of my favorite music, so it's hard to pick just one track from each album, but let's go with "Hello My Future" and "Could We".

To truly get into the depths of abstract electronic music, there are only four names you need to know: Warp Records label-mates Aphex Twin, Autechre, Boards of Canada, and Plaid. Plaid puts out the most approachable music of these three; the song "Squance" off their album Double Figure is what originally got me hooked. Aphex Twin's Drukqs is a work of art; it's best to listen to it as a whole album, but the track "Mt Saint Michel Mix + St Michaels Mount" is the best introduction on that album to Aphex Twin's music overall. Boards of Canada makes very ambient, but still strangely beat-driven, music that evokes memories of childhood in almost everyone who listens to them. Music Has the Right to Children is best sampled from the short track "Olson" and the longer "Pete Standing Alone". Finally, Autechre makes my favorite music of all. Their track "Arch Carrier", off LP5, is utterly transcendental. Their style gets more and more experimental as the years go by (which I love, though it gets them a smaller following every album), but "Arch Carrier" gives a great view of many aspects of their music.

This is all the best stuff I can suggest from the past five or so years. If you don't mind listening to something older, but new to you, I also heartily recommend the earlier albums of all of these musicians: Primus, Brian Eno, and Emerson, Lake, and Palmer. If you never listened to Nirvana, you must check out In Utero.

I've probably missed the deadline on this whole contest business, but I hope I can help you find some music you like!