Truth is; not much. Hands are great for puppets, sign language and clapping, but those things at the ends of your arms aren’t really that helpful in communicating a lyric. Frankly, overusing your hands in a song could pretty much sabotage what you’re trying to do on stage – which is connect with your audience.
Okay, so I’ll grant that “waving” at the audience is a fine way to connect, but after they wave back, ya still got nothin’…
Basic: My favorite guiding principle of hands is “keep them below your waist.” If you don’t know what to do with your hands, don’t do anything. If you feel like moving your hands, move them one at a time — below the waist. Stay away from emphasizing with both hands at once (parallel motion) or you’ll risk looking like a spokesperson for an infomercial.
Advanced: Moving a hand above your waist requires finding the best time to also bring it back down below your waist. If you absolutely must move a hand, move it during the last word of a sung phrase and then re-move it on the last word of the next sung phrase. Subtle – not slashing – motion required.
Summary: When singing a song, what’s going on in your eyes is far more important that what’s going on with your hands…