Lang asked, “Is this gandhabba the same word used in a different context? Or is it just mistranslated into “musician”.”
It is definitely not correct to say a gandhabba is a musician.
But as Seng Kiat points out, such descriptions are in dictionaries and in other texts.
As we have discussed, there can be human and animal gandhabbas. Both kinds have subtle “bodies” (more like “energy bodies”), that can get a bit denser by taking in the aroma (smells) of various kinds. Even then we cannot see them.
There are also some (lower level) devas called gandhabbas. In fact, there is a Tipitaka account of such a “deva gandhabba” who was a musician. I don’t remember the name of the sutta, but one time the King of the devas (Sakka) came to see the Buddha, accompanied by a deva gandhabba who was a musician (in deva loka). He played some kind of a musical instrument to get Buddha’s attention in that case.
– That could be how that definition got into the dictionary!