Before you commence each lesson or a practice session you must tune your guitar. If your guitar is out of tune everything you play will sound incorrect even though you are holding the correct notes.
If you want to play along with the other musicians or with your favorite recordings your guitar must be tuned to "concert pitch". This is a standard tuning that all musicians tune to so that they can play "in concert" with each other. It is possible for a guitar to be in tune with itself (e.g., you strum a chord and it sounds in tune) but out of tune with a piano which would be tuned to concert pitch. The following sections outline the methods you can use to tune to concert pitch i.e., electronic tuner, tuning to another instrument, tuning fork and pitch pipes. Also discussed is a method of tuning all guitarists must know i.e., tuning the guitar to itself. This tuning method is essential to know because when tuning to concert pitch you may only be given one note (usually the open 5th string A) so you have to know how to tune the other strings to this note.