Do you like to write melodies and lyrics? Is that where it stops? If it is, now might be the time to ask yourself why.
Perhaps you play an instrument like guitar already, but find that you're in a bit of a rut. Maybe all your songs are starting to sound the same, or maybe you're feeling limited by your knowledge on the instrument. The Sweet 16 chords are great, but they're only 16 chords, after all!
If you're looking to take your game to the next level, now would be a great time to learn to play a new instrument! There are so many benefits, both tangible and intangible, to diversifying your skill set.
For instance, if you're already a pianist and writing all your songs on piano, you might benefit from learning how to play guitar. New patterns and rhythmic structures are possible on guitar that aren't possible on piano or other instruments. You might find that playing with the new tones available to you really brings out the writer within that you never knew was there! Additionally, it's likely that you'll break through the rut with your first instrument, as the new one will start to make you approach your original axe differently.
If you're a performing artist, playing more than one instrument is really impressive to the audience. I know from personal experience, when I see someone who is a fabulous guitarist rock out at the drums, pick up the violin, or play a soulful piano solo, I'm always amazed. While we don't want to do these kinds of things just to impress others, it's important to acknowledge that that perception is there.
Lastly, whether you're solely a recording artist, primarily a songwriter, or exclusively a performer, having skills in playing a second or third instrument is helpful on a purely practical front. Your bassist might not always be available for a gig. Your piano player friend might be booked on recording day. You might have a band member quit 3 days before you leave for tour. Anything can happen, and being a working musician means being able to roll with the punches.
How about you? Have you found that learning a new instrument has improved your skills in unexpected ways?