Well here's an example: the picture shows a soprano chalumeau (Guntram Wolf, Kronach, scaled down from an original by Liebau since no soprano chalumeaus have survived) and a sopranino recorder (Moeck, von Huene after Rottenburgh). Also a CD for scale. The lowest note of the chalumeau is f' (the f above middle C) at a'=415 (so an e' at 440), the lowest note of the recorder is the f'' above that at a'=440, so a little over an octave higher.
I posted a few things on this thread along the way before I'd found out a couple of details. I'm in a position to tie up some of those loose ends now. Non-anoraks s'abstiennent.
It is indeed the case that no soprano chalumeaus (lowest note f') have survived. The surviving instrument that's often called one is basically an alto (lowest note c'); someone has over the years put a mouthpiece on it that's not at all to scale with the rest of the instrument so it now looks shorter than it actually was. (The highest it could have been is a whole tone higher than the alto or perhaps an alto at 466 which was also a pitch standard used at the time). The instruments that have survived are alto and tenor (lowest note f) instruments as well as a 'basson di chalumeau' (a sort of 'great-bass' instrument with a basic scale an octave below the tenor plus keys to give another perfect fifth below that; it's specified in continuo parts in a few Viennese operas around 1710).
One German musicologist, Jürgen Eppelsheim, wrote an article in the early 1980s contending that all or nearly all of the music that has been supposed to be for soprano chalumeau was either for alto chalumeau using a couple of notes in the overblown register (the chalumeau almost exclusively uses its fundamental register, hence the use of the name for the fundamental register of the clarinet) or for tenor chalumeau sounding an octave lower.
To me this makes sense for some pieces but not others. The obbligato in Vivaldi's Juditha Triumphans (which I think a few of us here know) makes a lot more sense an octave lower: it then moves in the same register as the strings and voice instead of sitting an octave above an otherwise close-knit texture although there are one or two cadences where it would dip below the accompaniment and be harmonically a bit iffy if it were an octave lower; still, there are some other odd issues with the string parts in the piece (not to mention the octave the tenor and bass parts are supposed to be sung at!) and at the very least the octave-lower version seems very much worth a try. On the other hand having looked through a fair bit of the Graupner material in Darmstadt a couple of days ago I don't at the moment believe he intended any of the music he wrote in the treble clef for the instrument to sound an octave lower; there are a few reasons but usually when he writes in the treble clef it's in unison with the violins, and some of the music if you were to take it an octave lower would make a complete mess with its accompaniment. There's also the fact that he normally wrote for the tenor instrument an octave
lower than it sounds, in the bass clef; having two separate conventions for the one instrument seems strange to me, as does the fact that Eppelsheim suggests some treble-clef parts sould sound as written, some an octave lower with sometimes no unequivocal indication which it should be.
One complication with the Graupner music is that he quite often writes down to e' for what otherwise look like soprano chalumeau parts. Sometimes it seems quite possible that the part was for alto (although in that case why didn't he write d' and c'?), sometimes it would work lipping down the lowest note or partially covering the end-hole (although lipping that far is very dubious on a single-reed instrument with the reed facing up, as it seems almost certain they played at the time; and putting an instrument the length of a sopranino recorder on your knee is to me a ridiculous thought in what are often very exposed solo parts). There is an alto which has survived which has one extra low note; a soprano version of that (
Andreas Schöni makes one) would work for nearly all of the doubtful cases.
No examples of the bass (lowest note c, i.e. an octave below middle c) have survived; it's clear the instrument existed from the music Graupner (in particular) wrote for it but exactly what it looked like is unclear, whether it was a 'straight' instrument basically like a tenor recorder with a reed on or whether it had some other design - the 'straight' model is apparently very tricky to build so that the cross-fingerings work.
I think that's probably more than enough information for now.
