A gentleman wrote me the other day to share his particular “hack” for playing alto that prevents him from learning all new positions. He wrote:
Most transposing instruments take C as their fundamental, usually, no valves pressed, so whatever their fundamental is, that’s their transposing key. When a horn in F plays middle C it really sounds like third line F. Now, a tenor trombone in Bb doesn’t play it’s fundamental as C that’s why is not a transposing instrument. In a tenor trombone, C is one step up from the fundamental (for the purposes of this argument let’s take C in the sixth position as our reference pitch, although strictly speaking the fundamental is below that). Take the C major scale from the sixth position and raise it a fourth, that’s what an Eb alto is playing when you play it like a”little tenor”. So when an alto, played as a little tenor, plays a sixth position C it sounds as F. If you read that “C” as middle C then you are a transposing instrument in F, you can read music written for F horn, or any other F instrument, right away. And there is a lot of music written and transcribed for the horn.
For an alto to be a transposing instrument in Eb, assuming we are playing it with the positions and note names of the tenor, it would need to be in Db. Such an instrument could read from a bass clef book thinking it is treble clef and adjusting the key, or straight from an Eb Real Book.
I am a math teacher so I always like to give my students more than one way to approach a problem. As I see it, there is more than one way to approach the alto trombone, for me it’s easier to adjust my ears (I also play a German baritone, a transposing instrument) than to modify the eye-arm coordination already built into my trombone playing. Actually, I thought I could build on that. I had tried the non-transposing approach before and it didn’t work for me, it wasn’t the alto clef, but the positions that proved a hurdle. Now, this approach has helped me get around the horn. Now, I can try to play it both ways.