What does it mean for the lute?
When the lute was revived in the 20th century, everyone assumed that it was tuned in equal temperament. Equal temperament is the tuning system in which the octave is divided into 12 equal semitones and enharmonic pairs such as D#/E♭ are the same pitch. However, as research into Renaissance and Baroque music progressed it became clear that keyboard instruments used different tuning systems, usually some variety of what is called “meantone” temperament. Many keyboards have “split” keys for some black notes, so that there are two separate keys for D# and E♭, G# and A♭. The use of meantone temperaments is also well documented in various treatises.
Once the virtues of historical tunings for keyboards were appreciated, it was natural to ask whether the lute might also be tuned in an unequal temperament, and in 1984 Mark Lindley published a book which examined this possibility. Lindley’s conclusion was that equal temperament was probably the most usual way to tune a lute, though for some periods and places (e.g., early 16th-century Spain) some adjustment of the frets to obtain better tuning might have been used. Since Lindley’s book was written, it has become very common for lute players to use unequal temperaments, largely for practical reasons: when tuned in this way the lute sounds sweeter, louder, and more in tune with ensembles including keyboards, harps, citterns and bowed strings. So are modern lutenists going against the grain of the historical evidence?
The evidence for equal temperament is compelling, but so is the evidence for a final adjustment by ear rather than a strict theoretical placement of frets. Gerle (1533) describes a method of placing the frets which approximates to 1/6 comma meantone rather than to equal temperament and his instructions were repeated by Dowland (1610) – see Dombois (1982). The vihuela music of Luis Milan (1536) consistently uses a difficult chord shape for an E major chord (nominal A tuning) rather than an easier one, the most likely explanation being that the major third of the chord was then placed on the fourth fret (a proper G#) rather than the first fret (an A♭): in fact Milan also explicitly suggests moving the fourth fret closer to the nut for some pieces (see Lindley, pp.51-57). Another vihuela composer, Fuenllana (1554) also recommends moving some frets for some pieces. Galilei (1584) advocates equal temperament, but in so doing he castigates those who use extra little frets (tastini) to produce the major and minor semitones of meantone temperaments, thus suggesting that some players did use them, though they are noticeably absent from lute iconography. Even without tastini, the easily moveable frets of the lute almost invite adjustment to suit the “key” of the piece being played: this might even be a factor in the grouping of pieces by key, in addition to the usual one of retuning bass strings.
In fact I think it is unlikely that lute players ever thought in terms of specific temperaments – they tuned by ear alone, without the help of any electronic tuning devices, and judged the results by ear as well. So they probably used a tuning which was close to equal temperament, but probably adjusted frets slightly in order to get a better tuning for some keys, or in order to be more in tune with other instruments.
For a clear explanation of the problem of temperament, and some discussion of baroque temperaments, I recommend an entertaining article by Ross Duffin.
A recent treatment of temperaments by Claudio di Veroli, including a discussion of fretting on lutes and viols, can be found in his eBook.
Bibliography
Dombois, E. “Correct and easy fret placement.” JLSA 6 (1973), 30-32.
-”-. “Varieties of meantone temperament realized on the lute.” JLSA 7 (1974), 82-89. Corrections in Vol. 8 (1975), 106 and Vol. 9 (1976), 108.
-”- “Lute temperament in Hans Gerle (1532).” The Lute 22/1 (1982), 3-13.
Lindley, M. “Luis Milan and meantone temperament.” JLSA 11 (1978), 45-62.
-”- . Lutes, viols, and temperaments (Cambridge: Cambridge University Press, 1984).