There are a lot of great ideas already posted for "scrub" playback options, but at the very least why not simply be able to audition or "scrub" notes by manually moving the green playback line back and forth? It seems like such a simple feature. It's a glaring omission that Sibelius can't do this. Having to put Sibelius in play mode just to hear a chord I entered is really kind of ridiculous. This would be especially useful for auditioning notes over multiple staves.
Idea No. 527