An establishment may not allow more than one accordion to be played for entertainment

No entertainment or music shall be provided or permitted for the enjoyment of the patrons of the establishment operated on public space by a permittee other than music as may be furnished by no more than three (3) musicians playing stringed instruments such as the violin, the viola, the cello, the double-base, and the guitar, and no more than one (1) accordion or concertina.