There are many benefits to your musicianship when you learn and master playing an instrument. You increase coordination, cognitive skills that include better memory, and create a higher level of social awareness.
The piano works as a wonderful starting point for most musicians, as it provides a good base in music theory, and it helps make identifying chords and key signatures a much easier task. But the guitar also provides an equally solid foundation for learning chords and is utilized just as frequently with songwriting. There are numerous advantages to learning and knowing how to play one of these instruments if you write songs. No matter which avenue you select, picking one of these classic instruments will undoubtedly assist and grow your songwriting abilities.