Play more than one instrument?

I played bass first.  Bass and guitar are very different.  I find it more difficult to play a good solid bass line and make it sound OK than it is to strum or pick a pattern over a set of chords and make it sound OK.  But that's just me.  Your mileage may vary. 

When you play guitar, you are playing in support of the lyrics and voice.  Usually, you emphasize the chords when you emphasize voice and vice versa.  Sometimes you add in a little fill, but mostly guitar and voice work together.

With bass, you are often playing a counterpointed rhythm and working fills.  You MUST maintain a rock steady beat.  Mess up timing with guitar and it's jazz.  Mess up timing with bass and it's wrong. 

So, while you are playing few notes at a time with bass, bass requires a very different mindset to play it well. 

I find it completely natural to sing and play guitar.  I cannot sing while playing bass to save myself. 

When playing chords on a guitar, you are often working shapes with muscle memory on your fingers.  You CAN play chords on bass, but usually it's two notes of the chord at once or arpeggios.  You've got to know your relative positions well.  It's possible to play guitar without knowing where the second of the root, or the fifth of the root is so long as you know what shape to put your fingers in.  With bass, you better know where the second or the fifth is.  In fact, it helps to know where two or three seconds or fifths (or thirds or fourths or sevenths) are.  You have to remember which notes to flat when playing minor chords, etc.

None of this is to say it's harder or easier to play bass, but it IS different. 

I found learning guitar easier because of the (limited) theory and scale work I've done on bass.  I tried playing guitar many times before, but after having worked theory and scale exercises to play my bass better, and THEN trying guitar, I found it pretty easy.  So there is definitely some overlap.

Hope that's not too long-winded and contradictory.

- Zurf

I  sing, play guitar,harmonica, bass guitar, and many various percussion instruments in a full-time, small-time band. I lay down the beef of my music with my guitar and color my music, via looping, with my bass and percussion. I find playing bass to be somewhat easier than playing guitar. I play rhythym and lead guitar simultaneously so when I add bass guitar to my loops it is a lower octave shadowing of what has previously been established. I do session work on bass as well and I personally find playing bass along with a lead guitar player much easier than playing  guitar leading a band.

I play
guitar, bass, jews harp, african tom drum, kazoo, mandolin, ukulele,banjolin

Ken

Guitar, tabletop drums lol

REALLY wanting to get some piano lessons (must be the Lennon fan in me)

I have enough trouble playing guitar without trying to learn another instrument but I have spent some time fiddling with my zoom drum machine. I love messing around with weird beats and fills and the playing my guitar in the groove

I played piano for a few years when I was younger, and clarinet in band. I kindof abandoned both of those, wish i would have stuck with piano in some ways, if only to learn music theory...
I play a little bit of mandolin, not enough to brag about, but I kind of follow along if somebody else takes  the lead.

All You Need is Love

I play the guitar, piano and harmonica and sing. Looking at learning the violin and/or mandolin. I find that learning the piano has helped me understand the theory behind other instruments and helps me be a better guitar player.

As far as the bass goes, many of the people I have played with share the thought of the other person, it is difficult to sing and play the bass also.

piano, violin, cello, guitar, clarinet, flute, harp ( badly), banjo, uke,
and, not an instrument in the common sense of the word but, my voice! ( 25 years of operatic training)