coordinator - someone whose task is to see that work goes harmoniously

systematiser, systematizer, systemiser, systemizer, systematist, orderer - an organizer who puts things in order; "Aristotle was a great orderer of ideas"

thinker - someone who exercises the mind (usually in an effort to reach a decision)

musician - artist who composes or conducts music as a profession

orchestrator - an arranger who writes for orchestras