What about practicing at home?
Play your Music Together CD at home. If there is a CD player in the car, it's also great to play the CD while driving. Do not limit its use to the car, though - children are less able to move to the music while strapped into a car seat!
Many children will want specific songs repeated again and again. Try to accommodate them by replaying their favorite track. They crave the repetition because it is necessary for their development. Repetition is one way they "practice".
Another way they "practice" is through spontaneous, playful imitation of the songs and activities they experience in class. These imitations will, of course, probably not be "correct" but they will certainly be fun!
Some children may not demonstrate interest in the recording. Right now, they may have different developmental needs and interests or simply have other current favorites. Perhaps they haven't adjusted to the class experience yet and are holding some enthusiasm in reverse! Just play the CD in the background, perhaps as they play or take a bath. Their interest in both the class and the CD will grow with familiarity.
The CD provides a way of reinforcing and following up on the class experience of live adults participating in live musical activities. The more you can continue this kind of participation at home by singing the songs or doing the chants and finger-plays yourself, the better it is, as long as you do it in the spirit of fun and enjoyment. Nothing sets a better model for your child than doing an activity you enjoy yourself.
Remember to use the songbook, even if you don't read music! Use it like a story book and "read" the songs to your child, especially the ones with pictures. In time, you might suggest that your child draw his or her own pictures for the songs, especially for those that don't have one!
Notice the effects of your child's experience in class and note his listening habits with the CD at home during the week. Write down or remember any questions you might have about your child's responses and then ask your teacher and discuss with other parents in class.