We all have to learn the facts of life at some time or another. Some find out for themselves; the rest of us have to be taught, and an exceedingly unsettling lesson it can sometimes be. I am, of course, referring to parallel fifths.

Consider Example 1. These two voices, keeping the same distance apart, are said to be moving in parallel motion. Since that distance, or interval, is a perfect fifth we have here a succession of parallel fifths.

During the period c.1400-c.1900, and particularly so during the 18th and 19th centuries, parallel fifths, octaves, and unisons were looked at askance on the grounds that they weakened the part-writing. The relative motion of voices in a given progression was governed by the need to preserve their identity as separate parts. Parallel intervals of the fifth, octave and unison were thought to endanger that identity. Clearly, to double a melody at the octave or unison, even for two successive notes, makes that melody stand out and effectively reduces by one the number of parts heard. Occasionally composers knowingly made use of this device whenever particular prominence or a certain tone colour was called for, later returning to a texture of independent voices. The effect of parallelism in the fifth is similar but less marked in its tendency to compromise the independence of the two parts. What was especially objected to was the actual sound of parallel fifths: a stark quality completely alien to the sound-world of this period.

Due to the nature of their instruments, composers of music for the guitar, lute, and vihuela often faced special problems in the avoidance of these forbidden parallel intervals. Example 2 is taken from Fantasia XXII by Luis Milán (1535).

Between the two chords marked with an asterisk we observe parallel fifths and octaves. To avoid these while maintaining a four-part texture he would have to write something like example 3.

While this is playable on the guitar, it is practically impossible for the vihuela, with its different tuning, to sustain the suspended D. To be frank, he probably wouldn’t have written this passage any differently had it been possible to avoid parallel fifths, a fact to which these progressions from his Pavana II testify (ex. 4).

It is characteristic of the two great lutenist-composers of the 16th century—John Dowland and Francesco da Milano—that they generally avoided parallel fifths. I say generally because they are to be found in their work though in the case of the latter only at the final cadence (ex. 5).

With Dowland it is tempting to think sometimes that he actually liked the sound of parallel fifths. How else to explain the following from the song arrangement Come Away (ex. 6) or this passage from Sir John Smith, his Almaine (ex. 7)?

Crafty harmony students will try to hoodwink their teachers and avoid parallel fifths by using passing notes. Example 8, from the tenth of Napoléon Caste’s 25 Studies, Op. 38 is a typical ploy but still constitutes parallel fifths. And from his fifth study (ex. 9) we find another old favourite—the device of delaying one of the voices.

Much to my annoyance none of these tricks ever fooled my own harmony teacher. He made me join the school choir, insisting it would improve my part-writing. He was right. Studying Handel’s Messiah every Monday for six months did for me what no textbooks could ever do: it heightened my awareness of the contrapuntal aspects of music.

It is not surprising, then, that Fernando Sor, a pupil of the choir school at Montserrat, should display in his part-writing a more or less secure technique. He did lapse occasionally, however, as we shall see. Giuliani ‘s technique was far from secure and often downright inept. Consider an excerpt from the second movement of his Sonata Op. 15 (ex. 10).

In addition to the parallel fifths, notice how the seventh in the second chord (G) skips up to B instead of falling to F# as it should do. Giuliani, when writing in C major, was awfully attached to a particular cadence (ex. 11) which appears at the end of studies number 1, 4 and 19 of his 24 Studies Op. 48:

Along with parallel octaves between bass and tenor, we have here a direct octave between bass and soprano (marked*). This occurs when an octave is approached by similar motion with a skip in both voices. Special rules apply between bass and soprano voices: where the octave is approached by a step in the soprano and a skip in the bass it is permitted but not the other way around, as in the case above. The same rules apply to the direct fifth.

There is but one case where parallel fifths were practised during this period: the resolution of the German sixth to the dominant (ex. 12).

Fifths were avoided between bass and soprano; they were most often seen between bass and tenor as in example 13 from Sor’s Sonata in C Op. 15 No. 2.

Notice how Sor fails to resolve the F# correctly. It should rise to G; instead the alto voice just disappears. This may be the work of an incompetent editor. I wish I could say the same for this progression (ex. 14) from the third minuet of Sor’s Deux Thêmes Variés et Douze Menuets, Op.11.

Containing, as it does, both parallel fifths and octaves it seems more characteristic of Jimi Hendrix than Don Fernando. Perhaps he played this passage with his teeth or possibly standing on his head, whereupon, by the process of inversion, the fifths would become fourths and no rules would be broken.

Jimi Hendrix built on Sor’s groundbreaking work by employing two perfect fifths moving in parallel in the introduction to his Castles Made of Sand (ex. 15).

Few would deny the effectiveness of this passage. There is nothing intrinsically wrong, then, with parallel fifths – in the tenth century, plainchant was often doubled at the fifth as are to day the folk songs of Iceland and many parts of Africa; Mahler, Debussy, Bartók and Ravel, to name but a few, have made use of them and they are everywhere to be found in popular music. It is simply that they sound bad in the context of so-called common practice harmony. Since many a budding composer uses this vocabulary it can be unsettling to learn of their prohibition—they feel all their previous work has been rubbished. Some will correct their work; others will wish they ‘d never been told and envy Madonna her unashamed, yet effective use of them in her song Justify My Love. Judging by her antics in the accompanying video it is highly probable that she is fully cognisant of the facts of life, though of any taboo pertaining to parallel fifths, it seems she remains happily ignorant.