“Bells Up” on French Horns
For French Horns there is quite often seen in score sheets a request to put the “Bells up” which is supposed to give them some extra volume and brassyness. Even some sample patches are available that cover this technique. Among horn players this technique is seen a bit controversial.
First of all, during regular playing the right hand of the player will be partially in the bell of the horn helping to shape the sound and pitch of the instrument and is an essential part of the playing of the horn. When raising the bell, it is tricky to impossible to keep the right hand in the bell which will give less control over the sound. Also due to the fact that the projection towards the back doesn’t change much, the difference in volume is argueable. The difference resulting in the sound comes mainly from the missing hand in the bell which makes the sound more brassy but also less cultivated which is often used as argument against this technique.
Some players might even refuse to do that technique at all. However writing that in, even if the players don’t execute it, gives them a hint of how you want it to sound and they might just play a little louder and intense without raising the bell.
As a side note, on live performances that technique has a way bigger effect as it is an impressive stage effect if you suddenly see the horns raising their bells. Gustav Mahler used massive orchestras and asked for that technique quite often (even on woodwinds). Seeing 10 horns raising their bell during a massively epic tutti has a very impressive effect.
However be warned about the use of this technique in recording sessions. Usually the mic setup is designed to work best with the “normal” playing of the instruments. A “bells up” might result in the bells coming closer to the spot mics and creating a very different (very direct) sound on them which might be a problem in the mix later on.