Yep I think library song was too little.
How the hell can you have 5000 songs?! omg
I have 3100 and that's just song. I have about 5x as many audiobooks (by time - 12.5 days worth of music and like 65 days of books). And I've had some rotten luck with HDD's over the alst few years. I was at 6 or 7k before.
Anyways, I've only used the Genius feature once, but it's pretty slick. I picked a fairly obscure song (Tin Foil Hats by Rocky Votolato) and got a playlist of similar, but not identical sounding, tracks from a variety of artists (Sufjan Stevens, Frou Frou, Elliot Smith, Neutral Milk Hotel, Ryan Adams, Bright Eyes, etc). Some are on my frequently played lists, but most weren't. Good way to get to some of the "B tracks" on CDs that I don't listen to often.
Anyways, this is a feature that I've been pining for a long time. I can't wait to try it on my touch at work. I often create on the go playlists based on my mood at a given time, but after the 10-15 minutes of making a 2 hour list and then another 30-40 minutes into and my mood changes.
😛
Now I can pick a song that reflects my mood and just insta-playlist... mood changes, pick a song for the new mood and instantly start a new group of tracks... love it love it love it.
Hm. Makes me want a 32gb touch to hold all my music.
😛 EVIL APPLE!!!
EDIT: Should start a thread to list the "source song" and the Genius list based on it.