This standard has been performed by all the great jazz musicians, and is essential for every vocal jazz library.  Superbly arranged with an understated Count Basie-style swing feel, it has some easy ensemble scat singing, but no solo demands.  It's easy to add a string bass and drums, or just let the piano lay down the walking bass line and play the tasty licks with the right hand.  This is perfect for the less-experienced group, yet hip enough for the more advanced jazz choir. Highly recommended!