Easy answer, they are way cool and work extremely well!

I’ve heard ascending Bb horns called the “poor man’s descant” but the fact of the matter is, if you look at what each horn does well, single Bb horns with ascending valves are lighter than descants and can play things like Beethoven and Mozart with a lightness and depth of sound that just isn’t readily available on the high f side. Of course, you can’t beat a descant when it comes to Bach Cantatas!

Basically, an ascending valve is one that remains open during normal horn operation, adding its length of tubing to the overall length of the Bb horn. When the valve is turned, it shuts off air flow to that section of tubing, shortening the horn and effectively raising the pitch one whole step. Here is a diagram of the air flow in my 4 valve Bb that I made with some incredible Adobe skills…

 

Short list of benefits of a Bb ascending horn

  • Easy high range. The addition of the ascending valve (taking the horn to C alto) allows you to play high Ab, A, Bb, and B on a shorter horn than is possible on a standard double. Using shorter horns gives a more stable and quicker responding note making it feel effortless.
  • More in tune. From about A below middle C, no note is played farther away than one whole step from an open partial on the Bb horn. This means a more even sound and better tuning because you aren’t using many 12 or 23 fingerings.
  • Full length leadpipe. With most descants, the high f side must have a very short leadpipe giving a sound that is more bugle than horn like. My single Bb horn gives all the lightness and ease of the descant but has the full 20 inch leadpipe. This ensures that the acoustics are sound and that not only does the high range feel good, it sounds good and is in tune.
  • Much cheaper than a descant. Alex descant: $8800. Schmid descant: $9000 Lawson USED descant (from HP.net): $11000. Medlin single Bb with ascending 4th valve (interchangeable with low f and stopping valves of course): $5000.