Further to my example a few weeks ago of a seldom-seen bass clef in a trumpet part, in the first movement of Mahler’s Third. I’ve never been good at reading any but the treble and bass clefs, but I did have to study the more common C clefs in solfège class at the Longy School in 1954. The rare clefs (baritone, mezzo-soprano, French violin) I have to figure out one note at a time. I’m fairly fluent reading the alto clef (middle C on the middle line) for viola parts, but if there are a lot of ledger lines I have to stop and think; I’m much less fluent with the tenor clef, though cellists, bassoonists, and trombonists use it easily all the time. (Cellists read the treble clef too, though they seldom encounter it. I know of just one example of a trombone part in the treble clef, in Ravel’s l’Enfant et les sortilèges. Ravel’s other opera, l’Heure espagnole, has a freakish instance of a contrabassoon (sarrusophone) part with a high B flat above the staff, but this involves removing the reed from the bocal and playing only the reed — you all probably know the place I mean.) (Example below. It’s a stunt common in rehearsal warmups.)
I can remember at least three instances when I had to scold pianists for reading the wrong clef after performances, plus two occasions in recording sessions, and at least one instance when I was conducting an orchestra rehearsal and a player gently admonished me for reading the wrong clef — I had incorrectly (read inadvertently) corrected her.
The problem is more serious when there are actual wrong clefs in the score, because these remain in print. Just last week, preparing for the Mahler, I found a missing bass clef in Trombones 1 and 2 on page 44 (six bars before no. 31 of the Dover score) and am glad to see this rectified in a later Universal printing. There are several missing clefs in one of the earlier pirated reprints of Petrushka — the printing is clearer because the engraved plates weren’t as worn as in later, corrected printings. For instance, in the old Kalmus mini score, one bar before no. 86, Harp 2, lower staff, needs a treble clef; no. 92, horns 3 and 4 and also over the page turn, must be in bass clef (compare no. 93); these missing clefs are corrected in the Dover reprint and in the Norton Critical Score. (There are many other errors in the old Russe Petrushka, let me add — not just clefs.) One incorrect clef that I find particularly cute is in the original Fromont edition of Prélude à l’Après-midi d’un faune, mm. 69-70 of Harp 2 (page 19 of the Dover score) — this should be a treble clef, not a bass; compare two bars before. This error is in Debussy’s own autograph full score. But of course it has been corrected in later editions.
In college I heard some tattle that there existed a recording of Stravinsky’s Symphony in Three Movements conducted by the composer himself in which, it was alleged, the cellos were playing in the wrong clef for a dozen or so bars, and this was not noticed in rehearsal or recording — but I have never been able to verify this. Maybe it was the Symphony in C; I can’t be sure, more than sixty years later. I do recall that just a few years ago, I got a letter from an electronic composer, saying that students found it difficult to hear the musical examples in Piston’s “Harmony,”,fifth
edition (revised and edited by me), and that instead of trying to pick them out on the piano students should have the opportunity to listen to them electronically synthesized, on a CD that could be sold with the textbook. He offered to do the synthesizing if I would provide him with a goodish deposit, and he enclosed a sample of his work. The sample he selected was Example 8-31, four bars from Couperin’s Les barricades mystérieuses, an unfortunate choice, because he failed to notice that this beloved piece is notated in two bass clefs throughout, and he had read the upper staff as a treble clef. You’d wonder whether it sounded funny.