Understand Note Clusters

Three clusters

Note clusters are notes that have the same number of sound waves but use different fingerings or length of the horn.

To understand this it helps to know that when we go from one open note to another we are changing the number of sound waves that are occurring in the horn.

When we play the lowest note we can on a length of tubing we make one sound wave that is the length of the horn. If we add some energy and break the sound wave in half the note will jump up an octave.

If you play the second F below the treble staff on your Bb horn you will be playing the fundamental, making one sound wave. If you slur up to the F below the treble staff you will have 2 sound waves in the horn, each 1/2 the length of the horn.

If you add more energy and break the sound into 3 waves, you’ll go up a fifth and get the C below the staff, middle C.  Add more and you’ll go up a 4th and have 4 waves. The more waves you have the shorter they will be and the higher the pitch.

When you play that middle C and have 3 sound waves and you push down your second valve, you still have 3 sound waves, you have just made each a little bit longer. If you switch that for 1st valve you will still have 3 sound waves.

Middle C and the B, Bb, A and Ab below it are in the same cluster. They all have the same number of sound waves but use different fingerings.

Every open note plus the notes between it and the next open note are in the same cluster.

Now for the good stuff! Slurring between notes in the same cluster can be done with just the valves! You don’t have to adjust your mouth, aim differently or anything else. Slurs done with just the valves in a cluster have a beautiful smooth sound.

You know that you are moving from one cluster to another if you go up and make the horn longer or slur down and make the horn shorter. These slurs can’t be made just with the valves. You have to adjust the energy going into the horn to change clusters.

If you slur from middle C to the D above it you are making the horn longer but going up. You can’t be staying in a cluster. You must add enough energy to break the sound waves and adjust for the slightly longer horn.

Conversely if you are slurring from D to C then you are making the horn shorter and going down. You have to add air volume to adjust for the lower pitch and decrease the energy somewhere (breath, chops or both) to re-connect the sound waves.

You can see how important it is now to slur quickly! To break sound waves or re-connect them takes energy, just like a karate master breaks a board. Would the master move the hand slowly or move it quickly to break the board?

Moving slowly spreads the energy out over time! Doing it quickly, led by the air of course makes for clean beautiful slurs.