You don't have to come up with these on the spot, either. Most places I've seen people singing or performing in RP, the song and/or act were prepared beforehand--either in a macro, or a separate text document. Pacing between each line is learned through just trying it out. Same with how much spam you're willing to put out at a time.
And to differentiate between song and speech, I'd use some sort of marker for it. I don't know how to (or if you can) get musical notes, but really anything that isn't used already, such as quotes or parenthesis, should work as long as you're consistent about them.
And to differentiate between song and speech, I'd use some sort of marker for it. I don't know how to (or if you can) get musical notes, but really anything that isn't used already, such as quotes or parenthesis, should work as long as you're consistent about them.
