I’m guessing they’re siblings, but I can’t say for sure. This early cabinet card photo came from a collection of musical ephemera in Boston, Massachusetts. (Two other posts featuring photos from the same collection are Music and baseball in the forest and “Waldfreunde” Mandolin Orchestra (1922).)
Do their outfits suggest any particular place of origin?
Despite their ages, these young musicians look like serious professionals.
I hope they found appreciative audiences!