Okay here it is: I used to be a drummer for 17 years before becoming a full time guitarist. And I used to teach as well. And here is the secret. " TIME IN MUSIC IS RELATIVE TO THE FEEL AND SOUL OF THE SONG" what that means is try not to stay rigidly structured to a certain time or tempo or BPM. tell your drummer to simply play the feel of the song. and the guitars and bass simply follow. I.E. if the jam is in 4/4 and there is a part that feels faster or slower than play a tad behind or ahead of the beat. and then use cymbals to bring it all back. listening advice would be KING CRIMSON; RUSH; METTALICA AND DREAM THEATRE...all great bands and also great drummers who know feel over time is essential to great music.Peace