2 players. Although it seldom occurs to us traditionally trained players, good deal of technique work can actually be done very effectively and efficiently with two players, in the same way as having a workout partner at the gym has advantages in motivation, pacing, rest & recovery. Where one player might normally work on an element of technique (pattern, scale or scale part, arpeggio, etc.) alone, two players can often accomplish more in both quantity, quality, and well, fun, as partners doing the same thing. Take the following example:
Play the major triad 1 3 5 through the cycle (i.e. circle of fifths descending: C F Bb Eb Ab Db F# B E A D G), 4 reps of the triad on each key; repeat the whole exercise 5 times. Player One goes first and then rests as Player Two does it. Player One immediately commences the second time through when Player Two is done, and so on, until they both have completed five times. The resting player may also serve as a coach, keeping track of reps, giving encouragement, small corrections, or variations (“Keep the pulse steady!”; “That’s it!”; “Now: two slurred and two tongued!”; “Last round – speed it up a bit!”; “Now two on each!”; “Now louder! Very soft!”; “Again!”; “Next time down an octave!”; “Good job!”).
The players should continue this type of exercise with a number of different challenges, e.g. using various scale types (major, different minors, pentatonic, whole tone, chromatic, etc.), different ranges, articulations, intervals, patterns, and so on, so that the whole session lasts 20-40 minutes. Even ten minutes of collaborative practice can do wonders. If at all possible, work with a partner three or four times a week – it’s always great fun and pays big dividends.