HARMONIC EXPANSIONS

CHAPTER 3: 6/4 LINEAR EXPANSIONS
3.7 The Arpeggiated 6/4

After two opening forte chords, Beethoven's "Eroica" symphony features a melody in the cellos which contains consonant skips in the tonic triad and which reaches scale degree 5 at the end of measures 4 and 5--see the piano reduction above. At these points second inversion tonic chords are briefly formed, indicated by the 6/4's under the staff. These 6/4's are called arpeggiated 6/4's, the name comes from the arpeggiations in the lowest voice.

Arpeggiated 6/4's differ from other 6/4's in at least two ways:

• Arpeggiated 6/4's are not derived from nonharmonic tone expansions. Rather they result from expansions by consonant skip.
• While these skips are common in instrumental music, they are rare in choral music, the traditional model for studying voice leading.

Nevertheless, for consistency within this site, the video to the right shows two arpeggiated 6/4s in a choral texture, one 6/4 expanding the initial tonic and the other expanding the dominant. Although the 6/4 in measure 2 is not part of a full arpeggio--it merely skips back and forth from the root--Music Theorists still call it, "arpeggiated."
In the first two measures of the fourth movement of Schubert's Piano Sonata D.850 (below), arpeggiated 6/4's are formed by the lowest note simply alternating from tonic to dominant. Repetitions of this kind are common in instrumental music.

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