Play-Along CD for Drummers Series: CDROM Product An intense selection of odd time tracks that will challenge you as well as prepare you for any prog or math rock gig. The best way to learn how to play in 7 is ... to play in 7! Here we cover 3's, 5's, 7's, 9's, 11's and throw in an occasional 6! Man, this is some fun stuff once you get comfortable. CD-ROM.