The holidays are over but some people are still on a toot. The management and the bands at the Chestnut Cabaret, Ambler Cabaret and 23 East remain in a euphoric state and that's why they're offering three nights of music - today, tomorrow and Saturday - without the usual cover charge. Tonight at 23 East, 23 East Lancaster Avenue, (896-6420) the music maker is Jellyroll; at Ambler Cabaret, 43 E. Butler Pike, (646-8117) it's No. 1 Band, and at the Chestnut Cabaret, 38th and Chestnut (382-1202), the sounds are by Separate Checks.



