It often featured rapid runs and arpeggios alternating with chordal or fugal parts. The opening theme consists of cascading arpeggios followed by murmuring chordal responses. In jazz, twelve-bar blues progressions are expanded with moving substitutions and chordal variations. Its main section features a melody with chordal accompaniment. The melody is repeated with a chordal accompaniment. The chromatic polynomial of a chordal graph is easy to compute. Both the bass instrument and the chordal instrument would play the basso continuo part. In modern chordal and melodic styles, a pick is frequently used. Apollonian networks are chordal maximal planar graphs, or equivalently planar 3-trees. First, the bass and drums are often recorded, followed by the chordal rhythm section instruments. Open tunings may be "chordal" or "modal". Interval graphs are chordal graphs and perfect graphs. The severity of flail leaflet varies, ranging from tip eversion to chordal rupture. The clique graphs of chordal graphs are the dually chordal graphs. Ptolemaic graphs are graphs that are both chordal and distance hereditary.