Doublings

(these guidelines were taken from class notes and from Aldwell and Schachter)

Generally, the preference is to double the root in root position chords

I, I6 (I, i6)

• Preferable to double root; then 5^th
• V7è I when melody goes from re-mi and (fa needs another mi to resolve to), it is OK to double the third
• Viio6è I and tritone is a d5, it is OK to double the third
• IV6èI6 (one of these chords will likely have doubled thirds, usually I6
• I6 can double 3rds if it is the smoothest solution (same for I??)

Ii, ii6, ii6/5, ii7 (ii^o, ii^o6, etc)

• In ii6, doubling 3rds is common since bass note usually doubled (doubling 5ths is less common)
• In ii7 sometimes doubled 3rds are necessary to avoid parallels (ii7 will be incomplete)
• When I==> ii7 (in major), often need to omit 5^th and double 3^rd

IV, IV6 (iv, iv6)

• When used to expand dominant (e.g., V-IV6-V6/5), 3^rd is doubled to introduce passing motion
• IV6èI, 3^rd doubled in one of the chords (usually in I)
• IV6èV (Phrygian), 3^rd above bass usually doubled (i.e., the 5^th of the chord)

V, V6, V7, V6/5, V4/3, V4/2 (v, v6, etc.)

• Don’t double ti (the 3^rd); other notes OK to double
• Don’t double the 7^th (fa) of V7; double the root if V7 is incomplete
• When going from ii(6) to V7, keep fa in same voice—this may lead to irregular doublings

V6/4, 7/5/3

• best to double bass note of first chord; if impractical, double the 6
• when vi==>V6/4—5/3. double the 6 (third) of V6/4 to avoid parallels

vi

• 3^rd usually doubled if it is used in a deceptive cadence and V(7) èvi in general
• in minor, third usually doubled to avoid aug 2^nd
• when going from vi==> V, 3^rd often doubled to avoid parallels

vii^o6

• root position rarely used—if it is, don’t double bass note (ti!)
• generally double bass note (which means the 3^rd is doubled)—it is not part of the tritone
• 5^th is OK if it is the smoothest solution and avoids parallels