Lots of 3/4 time and some that change time signature within the tune. Tunes that include root, two, three, four and five chords in the same tune. Not just the relative minors but modal structures that feature Dorian and Mixolydian modes. Not to contradict our moderator, but there lots of bluegrass and fiddle tunes that have minor structures. Breakdowns are often characterized by rapid tempos and unusual instrumental dexterity and sometimes by complex chord changes. This is in contrast to old-time music, in which all instruments play the melody together or one instrument carries the lead throughout while the others provide accompaniment. In bluegrass, as in some forms of jazz, one or more instruments each takes its turn playing the melody and improvising around it, while the others perform accompaniment this is especially typified in tunes called breakdowns.
