Grab Bag of Contrapuntal Keyboard Music Exercises
Scales. In contrapuntal music, scales are an essential resource. Within any small section of a piece, the notes mostly belong to a single scale (heavily chromatic music being a notable exception, but even then, there is a scale through which the chromatic motion is conceived to be moving). If your fingers can be told "limit what you do to notes in the scale such-and-such" and they respond without further command, this is a great savings of attention; it cuts the possible notes from twelve to seven, and allows you to focus on melodic contour and other things. For fingering scales in contrapuntal music, the only the general guideline to put your thumb on a white note; beyond that, whatever works, works.
Sight reading. The easiest and most fluent playing, even when sight-reading, happens when you can imagine, in your "inner ear," what the music sounds like, and you can play that sound by ear. Learning to sing (and especially, to sight-sing) is fundamental to this. Simultaneously playing and singing a single line is a good exercise to start with. It's essential to not look at your hands; if you can't stand not playing the right notes, don't look; just stop and feel for them. If you can't stop yourself from watching your hands, then practice something else.
Improvisation. We learn to improvise speech before we learn to read and write; to reverse this order would obviously be unnatural. Yet many people learn to play music from scores before they learn to improvise. There are reasons for this difference, of course; still, learning to improvise music improves one's ability to read music and vice versa.
Finger spacing. The musical keyboard has a spacing roughly equal to the spacing of an adult's fingers, but it's all to easy to miss the intended key, press two keys at once, or graze a neighboring key. Just as a violinist practices to play in tune, a keyboard player practices to attain the proper finger spacing.
Topography, Sequences. This exercise develops your sense of the topology of the keyboard within a certain scale. The simplest sequence is a scale itself: C, D, E, F, G, A, B, C... Somewhat harder is up two, down one: C, E, D, F, E, G, F, A ... Sequences can involve more than one part. Patterns for sequences can be taken from pieces of music.
Skeleton music. Extracting and playing the harmonic skeleton of a piece of music allows you to play something which is much easier than the complete piece while becoming familiar with the piece's structure. Practicing skeletons with increasing amounts of detail, you can move from mastery of a simple thing to mastery of a more complex thing, rather than moving from awkward struggling to less awkward struggling. These skeletons can also be used as a starting point for improvisation.
Seeking consonance. In this exercise, you pick a range of notes spanning at least a major third (for example, C, C#, D, Eb, E) and then play or sing along with a recording, playing the note which goes best with the notes you're hearing. Easier pieces are ones that move slowly, with sustained notes (for example, slow organ music) that give you time to find a good match. It is more difficult to do this exercise with a piece that moves quickly or is played on an instrument with a sound that dies out quickly (such as a harpsichord), because you will have to rely on your memory (either short-term, from having heard the notes, or long-term, from being familiar with the music). A variant is to seek out two notes, or all three notes of the chord.
Score following. When you are listening to a recording of keyboard music, follow along with the score, and imagine yourself playing the music. The vividness of this imagining is the key. Is there a term for the limb/digit equivalent of sub-vocalization? Your hands should follow the motions (and, if possible, the hand positions) necessary to play the music; for organ music, also feel the left-right motions of your feet. Your limbs need not move much, less than an inch, if that. This exercise is useful for both coordination and my fluency. Try to keep going as best you can regardless of how confused you get.
Score tapping. In this, you watch a score (preferably an open score -- one part to a staff) and tap the rhythms of the music on the paper, at the position of the notes whose rhythms you're tapping. The simplest is to tap a single line with one finger of one hand. Variants: (a) use more than one finger to do faster rhythms, (b) use fingerings in ways that suggest the melodic motion (quasi-keyboard playing), (c) use fingerings that would actually work on a keyboard, (d) tap two voices, one with each hand, (e) tap two voices, both with one hand, (f) move among voices, tapping the voice where things move the fastest, (g) move among voices, tapping the notes which are important structurally, (h) sing the notes you're tapping (either hand, alternate between hands).
Part-hopping singing. This is pretty much what it says: you sing a little of one part, then a little of another, doing octave adjustments when necessary to bring the part into your vocal range.
One-hand machines. (Incomplete) finger substitution, extracting exercises from pieces, thumb and finger crossing, multiple articulations, multiple dynamic levels, independence, finger spacing, dead reckoning...
Two-hand machines. (Incomplete) shifting focus...
Three-hand machines. (Incomplete) the "third hand" is played on pedals or sung...