That very much depends. Piano or guitar, arguably. In that once you've learnt finger shapes and patterns, they will sound good. The instrument itself will produce the tone. For example, you could just plonk your very first note ever on a piano, and it'll "sound" great.
Wind or string instruments are an entirely different kettle of fish. On the sax/flute/clarinet (my area of expertise), you have airflow to manage, tonguing to sort of and get fluent, embouchure (lip arrangement and pressure) and intonation to sort. It's a similar situation with stringed instruments.
It can take many many months to get to the stage where you can play three blind mine "competently" - i.e. in tune, in time and with a good tone on a wind, brass or string instrument. Anyone can do that on a piano inside 10 minutes.
