If you’re looking for a useful guide to determine royalty percentages when collaborating with other songwriters, here’s a simple way to calculate a general royalty percentage with respect to *musical* changes: where* e* = total events changed, *d* = quantity of the unit of metric measurement per bar, *b* = total number of measures, *n* = the smallest rhythmic value changed during alteration, and *R* = the total royalties earned (as a percentage). Remember, the value for *n* must be based on the shortest rhythmic value that is changed.

Example: John writes “Song X,” a 120-measure ballad using a 3/4 meter. Emily collaborates with John and changes 176 events at the *n*th-note level—in this case, say, sixteenth notes. (This could be 176 sixteenth notes, 88 eighth notes [*n* = 2], 44 quarter notes [*n* = 1], 704 thirty-second notes [*n* = 8], or any combination of such note values, but if we assume the shortest note-value Emily changed was (at least) one sixteenth note, the total amount changed should be based on the sixteenth-note value for *n*.

Therefore, the total number of musical events—based on the shortest rhythmic value of Emily’s changes—can be calculated as follows: . That is, there are 1,440 sixteenth-note events in “Song X,” (*bd* gives us the total number of musical events with respect to the unit of metric measurement), and Emily will earn the following songwriter’s royalty if she changes 176 (sixteenth-note) musical events: .

Simple—and pretty convenient if Emily begins clamoring for a 40-60 royalty split based on her efforts. We could also create a similar algorithm for “chord changes” (based on harmonic rhythm) and even lyrics, but we’ll leave those projects as exercises for the reader.