Tuners are easily one of the most important thing any musician can have. Maybe even more important than their instruments. Actually, no I take that back.
Tuners come in a few different types and the type that you purchase depends on the needs and skill of the musician.
The newest style of tuner is the clip on style, made popular by Snark. These tuners can be used either via a microphone on the unit or by detecting the vibration of the instrument. This makes tuning so much easier in high sound pressure situations like a band rehearsal or music store. They are simple, fast and easy to use. You clip them to the instrument, turn them on and it tells you whether or not you are in tune. These tuners are generally chromatic, so you have to know what pitch you are trying to get to in order to use it affectively. I feel that every musician should have at least one of these, since they work on anything that makes noise; even trumpets, clarinets and ukeleles. Many clip on tuners also feature metronome functionality, as well. For around $20-30, you can get them a tool that they will definitely need.
If your player is a little more stage oriented and finds themselves buried in high volume music like Rock, Country and Punk pedal tuners are the way to go. These are my personal favorite tuners to use. They tend to have wildly varying pricing and quality, but as long as you buy one made by a reputable company, you're gonna love it. I used one in my guitar rig before my pedal board. The beauty of the pedal tuner is that it will cut the signal from you guitar to you amp and keeps the crowd from having to endure you tuning up between songs and sets. The nicer ones tend to tune far more accurately than a clip on tuner, but at the same time costs as much as 10 times what a simple clip on tuner with cost you. I usually suggest either the Boss TU-3 or the TC Electronics Polytune 2. The Boss is generally regarded as a more accurate tuner while the TC Electronics Polytune is more conveniant, as it allows you to tune all the strings at once with a single strum. Boss even introduce the TU-3S, a pedal tuner that forgoes the pedal, it sits on your pedal board showing whether or not you are in tune at any given moment.
When accuracy is the primary concern most musicians will not reach for a clip on tuner, especially when dealing with acoustic string, woodwind and brass instruments. This is where you reach for your trusty stand alone tuner. Sometimes refered to as slab tuners or handheld tuners. My favorites in this range feature the Boss TU-12, one which I used heavily while gigging early on. I generally ran a line from my amp to the tuner, and I have to say: that tuner took a lot of abuse. The new model, the TU-12ex is supposed to be built much more robustly than my old model. Considering that mine is still kicking after 16 years really says something. These high end tuners are wildly accurate, durable and convenient, as they work either by microphone for acoustic instruments or plug for electric instruments.
If dropping $120 on a tuner isn't quite what you were looking to do and were looking for something with more flexibility, inexpensive chromatic tuners are a great way to go! They rarely cost more than $30 and feature a jack to plug into and a microphone. I can't count on my fingers the number of these tuners that have come and gone in my life, I even have one that is about 20 years old and still working.
Usually in the course of a musician's life, he or she will own at least one of each of these tuners and more than likely develope an affinity towards one. Being in tune is one of the most important things when it comes to playing music in any situation and having a tuner is a necessity no matter what the instrument.
Come on in to our store at anytime, we'll be more than happy to help you find the right tuner for the musician in your heart.