The Stradella bass system (also called the standard bass sometimes) is a type of button layout you find on the left (or bass) side of almost all accordions. It uses columns of buttons arranged in a circle of fifths.
Each diagonal column has, in order from the innermost to outermost buttons:
- The major third above (or minor sixth below, depending on which note) the root ("counter-bass")
- The root note
- The root note's major chord
- The root note's minor chord
- The root note's dominant seventh chord
- The root note's diminished seventh chord
Small accordions sometimes lack some of these rows, but for the purposes of this guide, we'll assume you have the full complement of buttons.
This is a chart of how a standard, 120-button bass layout will look like:
Tip: Consider printing out this chart and referring to it as you continue with this guide. You might find it helpful to have a visual representation of the directions described.
The middle "C" usually has a bump or hole in it for you to feel, to make it easier to find your way around the left buttons without looking at them. The A flat and E will also have some sort of marking sometimes.
Horizontal columns are arranged in a different order: every column goes up a fifth as you move up the bass board. So a "G" would be below middle "C", and a "F" would be above the middle "C", a "D" would be above the "G", and so on.
Most full-size accordion basses have either 120, or, less commonly, 96 buttons. All notes in an octave are covered by both systems, so you can play in any key.
When playing with the bass buttons, you use all fingers but your thumb, which should stay on the board on the side of the accordion.
Most accordions also have an air button on the side of the instrument that doesn't play any notes, but instead lets air in and out of the instrument.
If you have a large enough instrument, chances are there will be one or more switches next to the innermost row of buttons (near to the bellows). By pressing these, you can control which reeds in the left hand manual are sounding to create different timbres appropriate for the music you're playing, similar to the switches on the right hand.
In the next few pages, we'll learn the basics of playing either a simple accompaniment or melody on the basses. Just use the navigation below to go backward or forward.