mscuthbert
commented
2 months ago Its first appearance as far as I know is in a piece "Deducto Sey" by Antonio Zachara da Teramo c 1400 and then appears now and again in pieces about the underworld etc. (it only makes sense to use it when it's not on the first line and notes to below it [illegal! Says Guido!] since otherwise F5 would work as well)
The first appearances have it looking just like a modern serif gamma, so I think that would be the best (the crossbar might need to be squished a little bit to make it match the width of treble and bass clef). Later appearances show it just as a little hook (like a sans serif lowercase r ) as above and usually much smaller than other clefs. I would not recommend using that.
It appears often enough that I support Klaus's proposal.
A Gamma clef (defining the g under the F clef) should be added to the Medieval and Renaissance clefs section as exemplary shown in John Playford's An Introduction to the Skill of Musick, 1655:
It also mentioned in A dictionary of music and musicians, 1900.