The music selection in Ultramix 4 is vast, with 70+ songs and more on the way through Xbox LIVE downloads. It's definitely a bit more user-friendly than previous games too, with a good chunk of the tunes being more at the "beginner" level. But series fans shouldn't fret - you'll still find loads of songs on here for more advanced users as well. It's a really nice spread.
But unless you're a series regular - or you spend lots of time clubbing - chances are you're not going to recognize a lot of the songs in Ultramix 4. DDR's selection isn't nearly as mainstream as the stuff you'll find in SingStar, Karaoke Revolution, or the Guitar Hero titles. There are a few chart hits from Pussycat Dolls, Stray Cats, and Oingo Boingo, but more of it is electronica and house beats. Good music still, but not the stuff you usually find when flipping around the radio dial. Interesting to note is that four of the tunes are user-created, chosen in a contest earlier in 2006.