Music production seems like a great "embarassingly parallel" application since instrument voices tend to be independent and effects chains are readily pipelined

Music production seems like a great "embarassingly parallel" application since instrument voices tend to be independent and effects chains are readily pipelined. Multicore should provide direct benefit in terms of more tracks, more instrument voices, and deeper effects chains. What is the single-threaded workload that is sluggish? Is it something like encoding or compression?