Why do some jazz performances put me to sleep or make me irritable? Improvised solos using strings of even passages are mostly boring. Keeping a regular tone - no grace notes, no vibrato, no dynamics - makes me weary. Recapitulating the head with the same notes strikes me as uncreative. I’ll almost always prefer the soloist who plays with syncopation. Someone who plays with a sense of humor? S/he’s got my vote. Someone who changes up the texture by playing different rhythmic values or in a different range or with a different style.? Another vote from me.Improvisation is by definition arbitrary and unpredictable. Unless a soloist can keep my interest, I’d always prefer one chorus to 20. There are really not too many jazz players that can sustain a long improvisation. What about having a riff backing up a soloist? Too dated? I don’t think so. This is a sure-fire way to strengthen the music. Is it OK to use the same background figures for each soloist? Sometimes this kind of repetition works great. But I discovered that in one of my favorite arrangements - Eddie Durham’s 1937 arrangement of “One-O’clock Jump” for Count Basie - each soloist gets a different background figure.I guess dissonance is hip, and so is non-danceable meters. Do I care? Is unrelieved dissonance effective? I don’t think so. The self-serving composer Arnold Schönberg told his 1940 composition class “There is still plenty of good music to be written in the key of C major.” His own music was wonderful before he developed his own theory of unresolved dissonance and stuck to it.When you combine together relentlessly even passages, regular tone, unrelieved dissonance, little or no syncopation, no background figures and lengthy improvisation you get the musical equivalent of a browbeating. If you “don’t get it,” sometimes it isn’t because you aren’t hip enough.