Because people often ask, here’s the answer: a piano accordion is an accordion that has piano keys on the treble side.
A full-sized piano accordion has 41 treble keys, arranged the way they would be on a piano, and 120 bass buttons, arranged in 6 linear rows of 20 buttons each. That might seem like a lot, but because the arrangement is both logical and consistent, finding the buttons you’re aiming for isn’t as daunting as it first appears. Also, even if your accordion has a full complement of buttons–and many do not–you don’t have to play all of them.
Piano Accordions: Bass Layout Logic
On a piano accordion with a Stradella bass, which is far and away most common, each short diagonal row–6 buttons on many accordions–is in a specific key. What each of those buttons plays is a function of its placement within that diagonal row.
All of the buttons on the vertical row closest to the bellows play the 3rd of the chord, often called the counter-bass. The button on the next vertical row, 2nd from the bellows, play the root note of the chord. The 3rd row plays the major chord; the fourth; the minor chord; the 5th, the 7th chord; and the outer row, the diminished chord. If you’re on the C row, for instance, you will have an E note, a C note, a C major chord, a C minor chord, a C7 chord, and a C diminished chord.
Once you find the C bass note–look for a button near the middle of the 2nd vertical row that has a tactile marking of some kind, typically a dimple, a hashmark, or a rhinestone–you will have found the entire C row. From there, if you move up one button, you will be on the G row; if you move down one button, you’ll be on the F row. And so on, both up and down. In music-theory-speak, the rows go up in fifths and down in fourths. That means the one, four, and five chords are always adjacent, regardless of the key signature. Because many tunes use primarily those chords, this arrangement is user-friendly.
Piano Accordions: Variable Features
Smaller accordions sacrifice range in both treble and bass. Many people don’t need the outliers and don’t miss them, but keep in mind that on the bass end, you need at least 12 diagonal rows to be able to play accompaniment in any key. Many people find that a 72-bass accordion (6 x 12), which typically has 34 treble keys, starting on the G below middle C, is a good solution to the weight vs range conundrum.
Piano accordions also differ in the number of reed banks they have, the octaves in which the reed banks play, and the amount of tremolo in the tuning. Some piano accordions have switches that let you vary which reed banks play and which do not; some have a tone chamber, which modifies the sound quality; some have full-sized keys and some have keys that are narrower or shorter; some have lots of rhinestones, some are so subdued that they are almost tasteful, and some are beautiful. Like Cleopatra, their variety is infinite, almost.