If you play an instrument, there is one thing you absolutely must do, every time, before you begin playing. Deciding not to tune your instrument before a concert or show is the same as saying you want to do a bad job. You can be a skilled musician, but if you’re running flat or sharp, it’s not going to sound very good at all.
Even if you have a good ear for what the correct note is, like those with perfect pitch, it’s still a good idea to use an electronic tuner here and there. This Snark Tuner is one such device, and from a speedometer-style full color display, it will show you if you’re even the tiniest bit off. If you’re flat, it will tip left into the red, and will lean into the yellow if you’re sharp.
The display can rotate 360 degrees, and it uses a bendable support, so you can easily see it regardless of how you want to go about the tuning process. Thanks to these two aspects, it can be used on the front or the back of the headstock. This is aimed at frequency ranges for guitar and bass, though I’m sure you could use it on a variety of other instruments as well. This is only going to cost you around $10, and uses a CR2032 battery which shouldn’t be too difficult to find a replacement for once every couple of years.
Available for purchase on Amazon