Rhythmic  NOTATION
This may look like music "theory", but it is really button-accordion "reality", except for the references to time signatures (such as 2/2, 3/4, etc.).  We prefer, up front, to identify the beat symbol and state the number of beats per bar, using simple English.  

An example for Part 2 below:
                                               Number of beats per bar = 3
                                               Beat symbol = the period, or dot  ( . )
1.  Bars - Where Beat Intervals are Grouped.

Up to this point, our notation has focused on playing the treble (right-side) buttons, giving us melody and melodic rhythm.  Now we need a notation that will guide the playing of the left-side (bass and chord) buttons, to accent the "beat".  

We will use the bar (or measure) notation, where groups of beat intervals are separated by vertical bar lines for this purpose.  Unless otherwise indicated, each bar in a tune contains an equal number of uniform beat intervals.  For example,
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  • if the time signature is 3/4, indicating three beat intervals in each bar, the groupings might look like    | .3   .4    .5  | .:6  | .:7* | .6*  .5*  .5  |  .:5*  |  .:5   |       with three dots (or periods) in each bar.

  • if the time signature is 4/4, the groupings might look like    |  .4    .4    .4*  .5  |   :4*   .4   .3*  |   where there are four dots (or periods), indicating four uniform beat intervals, in each bar.

  • if a note is to be held for more than the designated duration, the button number will be followed by the tilde symbol, such as   | .:6~ |  .5*  :4  |  where button 6 in the first bar is held for more than three beats, but the tune returns to three beat intervals in the next bar.  Unless otherwise indicated, the player decides how much longer to hold button 6.

  • if a note is carried over from one bar to another, it could be written as    |   .:5~ | ~:    .4   |    showing  that button 5 is held for a total count of 5 beats (three in the first bar and two in the second bar) and then button 4 is played for one beat interval to complete that bar.

The bars can help the accordion player use the left-side buttons to establish an underlying or basic rhythm, commonly called the "beat".   The first beat in a bar is normally given a greater emphasis than the other beats.  Possibilities include:

  • Playing the bass button on the first beat, followed by the chord button on the second beat, and so on, appropriately matching the bass and chord buttons to the key being played.

  • Playing the first button louder than the second button which follows it.

In general it is not a good idea to hold the bass or chord button for too long, as you tend to run out of air-flow.  Thus short taps using the first option above (sometimes augmented by the second) may be better. 
  • In 2/2 time or 2/4 time, the left-hand rhythm is commonly  | Bass-Chord | Bass-Chord |  Bass-Chord |, where each Bass note is given the same emphasis.  (Covered in Unit 8 of our mini-course)

  • In 3/4 time, the left hand often follows the rhythmic pattern  | Bass-Chord-Chord | in each bar.  (Covered in Unit 9 of our mini-course.)

  • In 4/4 time, the left-hand rhythmic pattern is commonly  | Bass-Chord-Bass-Chord |,   where the first Bass is given greater emphasis than the second Bass, which is different from the chord. 
  • An alternate 4/4 pattern is   | Bass-Chord-Chord-Chord.  (Covered in Unit 10 of our mini-course)
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An ASIDE: 
Bars (or measures) are even more important for an ensemble of multiple instruments (as in a band or an orchestra).  Here the beats in each bar, with their different emphases, help to keep the instruments playing together, so that notes that are intended to be played together by different instruments, actually are.
2.   Bar Example - Morning Has Broken
    
 Each bar (between the vertical bar lines "|" ) is a counting region, where we play the BASS and CHORD buttons.  Because these button locations vary with accordion type and musical key(s), we cannot be more specific in the general Accordion Notation.  
The Haley Westenra youTube video at right is in the key of C for verses 1 & 2, then in D for verse 3, returning to C for a final singing of verse 1.  
   
It follows a 1 - 2 - 3 (waltz) pattern, which can be illustrated as follows for the first line:

    Sing      Play R.H.     Count      Tap L.H.
   "Mor-"          .3              1           BASS
  "-ning"          .4               2          CHORD
   "has"           .5               3          CHORD

  Sing      Hold R.H.     Count      Tap L.H.
 "bro-"          .:6               1            BASS
                                       2           CHORD
                                       3           CHORD
 
  Sing      Hold R.H.     Count      Tap L.H.
 "-ken"         .:7*              1           BASS
                                       2           CHORD
                                       3           CHORD

  Sing      Play R.H.     Count      Tap L.H.
 "like"           .6*              1            BASS
 "the"           .5*              2            CHORD
 "first"          .5               3            CHORD

  Sing      Hold R.H.     Count      Tap L.H.
 "mor-"         .:5*             1           BASS
                                      2           CHORD
                                      3           CHORD
 
  Sing      Hold R.H.     Count      Tap L.H.
"-ning"         .:5               1            BASS
                                       2           CHORD
                                       3           CHORD

Morning Has Broken  (Time signature: 3/4)

|   .3    .4     .5  |  .:6  | .:7*  | .6*   .5*   .5   |  .:5*  |  .:5   |
  Mor-ning has   bro -  ken,  like  the  first    mor  - ning,

|   .3     .4      .5   |  .:5   |  .:5*  |  .5    .4     .3   |  .:3*~|~ .:  |
  Black-bird  has    spo -  ken,    like  the  first    bird.

|   .5    .4    .5  |  .:6   |  .:5*   |    .5      .4   .3* |   .:3   |   .:3*  |
Praise for the    sing  -  ing,    praise  for  the    mor  -  ning,

|   .4     .3*   .4   |   .:5     |  .:5*  |   .3*    .4    .3*  |   .:3~|~.:  |
 Praise for them  spring -  ing     fresh from the    world.

Note that at the end of the second line, you sing "bird" while playing .:3*~ for a count of three, and then continue to hold this note  ( 3* ) for an additional count of three ( ~.: ).  There is a similar carry-over of the .:3~ note at the end of the fourth line.
Continue with the remaining lines, following the same uniform 1-2-3 counting and BASS-CHORD-CHORD tapping rhythm for each bar in the song.  Don't be discouraged if it feels "impossible" at first to do different things with the two hands ... keep trying and your brain and fingers should eventually get into it.

Remember that the left hand is providing a beat rhythm, so don't hold the left hand notes too long, just tap (perhaps, as though you were a slow one-handed drummer).   Apart from not sounding quite right, "holding" the left hand notes too long for some tunes can cause you to quickly run out of air, closing, or dangerously extending, the bellows to its limits.