Which musical instrument would you like to master, if given the chance?

recorder. the recorder familly is huge and has a great tone

I have already had a few years of experience in flute, and of course would love to master that.  But I've also had the opportunity to dabble in clarinet, bass drum, French horn, and guitar.  Classical guitar has become one of my favourites to just pick up and play around with, but French horn was one that also stuck with me because of its gorgeous, warm tones.  I never had enough time to sound good haha - I'm definitely not a natural brass player - but I dream of mastering it.  I also love the unique grace of an oboe ... if I could get past the initial stage where you sound like a duck without dying of laughter!

Violin.  I’m already an excellent piano player

I play keyboards, bit of bass and guitar.  Although I play piano/keyboards to a reasonable standard I would like to master it which would be difficult considering the standard of music written on it.  Same with bass.  As for a completely new instrument - drums.  All these instruments compliment and inform each other wonderfully.

I'd like to master the bassoon.

Any serious player of an instrument will tell you that we do not use the term "master" in referring to our selves or studies.  There is always someone that you hear that humbles and inspires you- this inspires further learning and further practice.  I started piano lessons in 1957  and flute lessons in 1962.  DH and I pianist, flutist) - and our adult son and his wife, now (pianist, singers) - have earned many degrees in music from fine conservatories, and all made careers in music.  None of us - nor any of our peers - would ever call ourselves masters - even though some of the diplomas say that.  We just keep learning and practicing.  There is no end - that is the glorious part.

The instrument I've played for decades - the guitar.

My own voice.

I am a classically trained violinist and pianist.  I have also dabbled in cello and sax.   But I can't sing for shite.   I don't even like to sing Happy Birthday at parties.  It's a bummer since your voice is an instrument you ALWAYS have with you.