A system and process for producing a more harmonious musical accompaniment for a musical compilation, the process comprising determining a plurality of probable key signatures for the musical compilation, creating an interval profiling matrix for each of the probable key signatures, finding products of a major key interval profile matrix with each of the interval profiling matrices, summing each of the major key interval products into a running major key sum, finding a product of a minor key interval profile with each of the interval profiling matrices, summing each of the minor key interval products into a running minor key sum, and selecting the most probable key signature from the plurality of probable key signatures by comparing the minor key sum and the major key sum.