Drum keys (as in "multiple drum keys") should be in the stick bag and keychain of every drummer on the planet. They can be as simple as a three-prong turner, a crank-based model, or an auto-tuning deluxe unit. Just like any other instrument, your drums won't stay in tune forever -- especially if you're constantly beating on them. Check out Reverb's selection of drum keys and tuning tools like the DrumDial and Tune-bot drum tuners.