[squarefoot]

Knowing how to tune a guitar (bass, etc) is one of the first thing any player should learn, but next to it are recognizing that your guitar is out of tune and how to make sure you don't have to retune it every 5 minutes. The first comes with practice and musical training and the second requires a good knowledge on how to mount strings. A string fixed the wrong way will force the player to tune at every song or more often, so learning how to put strings in place is vital. There is a self-locking technique well explained in youtube videos; look for it because it will come very handy.