The register, or coupler, buttons can be found on most accordions. But how do you use them and what do they do?
Each time you switch registers with the coupler button, you are opening and closing a slide on the reed block. This allows you to play one or more reeds at once. These reeds can be in different octaves. They can also be in the middle register, but tuned slightly apart.
By understanding what the register buttons represent, you can determine what the layout and reed configuration of the accordion is before even playing a note. This is handy to know when you are buying an accordion.
An accordion's reed blocks can be understood by a combination of some or all of the letters LMMMH:
"L" being the Low register.
"M" being the middle registers
"H" being the high register.
When the master switch is selected, all the reeds play at once from the note pressed down.
LMM, for example, means your accordion is a Low/Middle/Middle+ 'voicing'. Voicing is the character and sound of the reeds you can play together.
Some accordions will have names of instruments, or music notation, instead of the letter symbols. But they represent the same thing. A "Bassoon" switch equals the "L" register; the "Clarinet" switch equals the "M" register; and a "Violin" switch equals the MM+ middle registers. Accordions can have between 2 and 13 coupler buttons.
Understanding how these switches work will give you knowledge about what type of accordion you may want to play or buy. But you will also be able to make changes to suit different songs and add variety to your sound.
A final tip. When checking the tuning of your accordion, pick out a single register and the A4 note/octave of that register. You may find that your accordion is tuned to A440Hz, A442Hz or A443Hz - and that is valuable information too!
- Tony Peri, Reedworks.