What are the disadvantages and advantages of playing a guitar?

DISADVANTAGES:

• It’s harder to read standard notation on the guitar than any other instrument I’ve ever played. Most instruments produce a pitch in very few ways - middle C on the piano is always in the same place, and it’s just one key. The guitar can produce that pitch in five different places. Sheet music for piano is basically “hit this key now”, but for the guitar it’s a decision making process. The guitar is also capable of playing both horizontally (melody lines) and vertically (chords). The learning curve to read well on the guitar is easily twice as long as any other instrument.
• Finger dexterity is needed in two different dimensions - you’re reaching across the fretboard and along its length. Other instruments are much more limited: trumpet valves just move up and down. You reach a little bit for the black keys on a piano, and have some odd fingerings on other instruments, but in terms of the different ways fingers have to move, the only instrument that rivals the guitar is probably the bassoon.

ADVANTAGES:

• Fretted instruments are the easiest to transpose on. If you learn a C major scale on piano, it’s not going to help you play in Db. You’ll need to learn the actual notes (Db, Eb, F, Gb, Ab, Bb, C, Db). On the guitar, assuming a fingering has no open strings, you simply move up one fret and voila - Db major. This is a HUGE advantage when you’re reading standard notation and the singer wants to take it up or down a step or two - you just move your hand, and you pretend you didn’t (if I’m in second position D and the singer wants it in E, I move up two frets and imagine I’m still in second position and everything is perfect).
• The guitar is really expressive. Bends, slides, slurs (hammer-ons and pull-offs) and vibrato are all fairly easy techniques to learn, but they add a ton of possibilities to your phrasing.
• It’s self-contained. Because the guitar is capable of both melody and harmony, you can do a decent solo arrangement of just about anything.
• It’s one of the simplest instruments to start making music with. Learn two or three chords and you can play a song to accompany your singing.