i know im 8 months late but when i play behind a soloist i learned that if you try to follow them and you dont know the song its harder to pick up the pattern to the song so i just let them sing and the next time around i get them but i put them in key first. The key to following is to know the song and accompany not lead and your slightly behind the soloist until you there is silence and/or you bring them to the next part of the song. The soloist and the musician should work together!!!