head arrangement
A musical arrangement worked out collectively by ear rather than written down.
In Depth
Head arrangements are created collaboratively during rehearsal, with musicians contributing ideas and memorising their parts rather than reading from a score. This approach was common in early jazz, rhythm and blues, and soul music. Count Basie's band was famous for head arrangements that sounded so tight and polished that audiences assumed they were written. The head arrangement approach values spontaneity and collective creativity, producing music with a natural, organic feel that fully composed arrangements sometimes lack.
Count Basie's signature head arrangements were so well-rehearsed that the band could create spontaneous-sounding dynamics and accents with split-second precision, all from memory.