While rendering the score for Beethoven’s Violin Concerto, I got bit by Dorico not catching an instrument change. Specifically, the clarinet is in ‘A ‘in movements I & III but is in ‘C’ in movement II. A clarinet is, of course, a transposing instrument – meaning the actual tone produced is different than written.
There must be some lack of clarity somewhere in the MusicXML standard in that Dorico simply sees a staff as the first instrument title encountered and then cannot notice a later change in instrument in the document. It’s not the end-of-the-world though because there’s a process in Dorico to handle players using more than one instrument. What is crazy though is some the hoops that you go through converting changed section.
Since Dorico missed the change of clarinet from an A clarinet to a C clarinet, it presumed an A clarinet during the new section. The key is all wrong (for an A horn) and it sounds like a sick calf. Ooo boy – we got some work to do.
Really, the point of transposing instruments isn’t to be obtuse but to normalize the playing techniques across a range of musical key signatures. This is really apparent with woodwinds – a larger instrument has a lower range and root note than a smaller one of the same type. The first hole on a clarinet differs in pitch depending on which size of clarinet is in use. To make things easier for the instrumentalist (player) the keys are treated as a C scale no matter the size. This makes it possible for the player to switch from an A clarinet to a B flat clarinet to a C clarinet using the exact same fingerings.
It takes a bit to get used to notion of a transposed instrument from a composition standpoint, but for the instrumentalist, it’s inconsequential. I played a B-flat cornet as kid and had no problems with it. You play the notes as written. Sure, when you play a ‘C’ on that cornet, a B-flat is what sounds but you’re not thinking about that.
The solution to instrument switching in Dorico is to consider the staff as belonging to a player. You simply assign another instrument to that player. Now, the clarinet player in Dorico has two instruments, in this case the A clarinet and now a C clarinet as well. In galley mode Dorico will show a staff for each instrument of that player. It’s only when you switch to engrave or print mode do you see the instrument/key change on a single staff.
Getting back to the Dorico solution – simply move the clarinet notation in movement II to from the A clarinet staff to the C clarinet staff for that player. I can’t simply just use this though as is; I have one more step.
Our problem entails the correct notes for a C clarinet but shown incorrectly on an ‘A’ clarinet staff. Since simply copying the notes from the A clarinet staff to the C clarinet the C clarinet will cause Dorico to transpose them for a ‘C’ clarinet, we must manually undo that by shifting the notes back up a minor third (the interval between C and A). As for Dorico automatically transposing notation from one instrument to another – that’s normally a good thing. You want that so you can use whatever instrument an orchestra happens to have or normally uses.
Lastly, this is a learning moment for me to pay closer attention to details. It does seem odd to see a movement written in D major (two sharps) and then see the Clarinet in A shown with one flat. That’s the key ‘F’ major, what gives? Well, the key noted key signature for a transposing instrument is changed to match the physical instrument up to the piece’s key signature. Since A follows the D, there’s a difference of -1 place on the circle of fifths. That’s easy enough.
So – if we go one place backwards from C (the A clarinet’s transposition) we wind up with F. Confused? Heh – I had to step back a few moments and consider things too.
The French horns switch from D to G also, in the second movement. In their case, Dorico did catch the switch, but transposed the notation for them from D horns to G horns – which is why they looked funny to me but sounded correct. I thought about it for a moment and switched them back to D horns, just to be OCD.