The Korg GT-3 is a general guitar tuner for use in any capacity. It's probably best suited for use during practicing rather than live shows, but it will work fine for any situation where you want to tune. It's got both a 1/4" input and output and a built in microphone, so you can tune either electrically or acoustically. This tuner also doubles as a bass tuner, as it is designed for either purpose. It also has a meter showing if you're sharp or flat, so you've got pretty much everything you need to tune up quickly right here. We have one of these at the studio where I work, which runs on batteries so I'm not sure if it also has a power supply option as well. So while the GT-3 isn't the most in depth tuner out there, for simple tuning purposes it will work fine for guitar or bass guitar. I'd probably recommend this mostly for beginners or those who won't be playing in a live situation, as this isn't the best tuner for a gig. The reason is that it might be hard to see in the dark and you'd have to plug into and out of it. The Boss TU-2 or TU-3 is definitely the way to go if you're looking for a tuner for live shows, although it will cost you a good amount more than the GT-3. As far as cheap and simple tuners go, the Korg GT-3 is really as good as any out there, as even though it doesn't stand out too much, it's very reasonably priced and will get the job done just fine. It definitely isn't flashy and doesn't have a real chromatic mode, Korg does make some of the best tuners out there, so even their cheap models are above average like this one...