Hallo, Helmut,
Daß man für den Auftritt eines Musikers / einer Band gerne
auch auf neuhochdeutsch „gig“ sagt, ist mir bekannt,
allerdings frage ich mich, was hinter dem Wort steckt
(etymologisch).
das lässt sich nicht eindeutig klären. Eine kleine Auswahl zur Etymologie:
„job,“ first used by jazz musicians, attested from 1915 but said to have been in use c.1905; of uncertain origin.
http://www.etymonline.com/index.php?search=gig&searc…
…Most dictionaries say that the origin of „gig“ in this sense is unknown, but it really doesn’t seem that great a mystery. Appearing in English in the 15th century, „gig“ meant something that spins, as in „whirligig.“ Subsequent meanings included „joke,“ „merriment“ and (aha!) „dance.“ Since playing at parties and dances is every musician’s meal ticket early in their career, it’s easy to see how „gig“ became generalized to mean any paying job.
http://www.word-detective.com/back-n.html
…The origin is unknown, but it may come from the slang term gag. This dates to 1890 and means business method, practice, or behavior. All these sense are American slang usages.
http://www.wordorigins.org/wordorg.htm
und ein ausführlicher Artikel auf
http://www.worldwidewords.org/qa/qa-gig1.htm
Gruß
Kreszenz