Playing by ear

Unlike on instruments where the note fingering is determined by physics (e.g. any wind instrument) or history (e.g. the piano) a novice can easily play a piece in any key on a jammer. This makes it feasible to play along with any piece you know well and like.I've found it actually works well.

Warning! Playing by ear takes careful practice to prepare a presentable product.
As with learning to sing, preparing sausages or political dealing, this is very much a deed best first practiced in private.

Prerequisite: First learn well the “Folded" scale pattern of the jammer scale as documented elsewhere in this site.  In other words, your fingers must roughly know where to find the notes.

It’s a bit harder than playing a piece in straight C (all white notes) on the piano; but it’s easier than learning to play any other key; black notes are a world of complication.

Playing along with a piece*

Listen for the pattern, play along in your best guess, and shift left or right (this shifts the pitch {the key} you are playing by a whole tone) depending whether you are below or above the key, until you either hit the 

Jammer semi-tone steps

mark or overshoot. If you over-shoot, either go up one row diagonal-left and left three keys or down-right one row and right three keys (this shifts you down a semi-tone). This sounds complicated but is much more a skill for your fingers and ears to learn than for you to learn. A helpful picture is here:

The colouring of the notes should help here. As hoped, I’m finding that the colored notes are starting to develop a "sound feel" or "sound personality". This vastly helps to link the notes heard to the notes played.

Once you are playing the right notes, shift your fingers along until you have your little finger and your index finger making the right-feeling break between the two rows of music. Lets call the lower row the Root row and the upper one the Dominant row. Your middle finger has now found the key (if the song in a minor key, the ring finger is on the key).

Music is simple - the piano makes it look hard.

* Aids to doing this: Link to be added allows you to play a Mp3 or midi file at your own pace, and to loop repeatedly over just a section of it.