Bradley Lehman video: “Harpsichord tuning: 17th-Century regular… morphed to Bach’s”
Xa é o terceiro vídeo sobre afinación que tomo esta semana do canal en YouTube do doutor Bradley Lehman, investigador e intérprete de cravo e órgano.
Neste vídeo, por fin, toca dúas pezas de música como exemplos. Primeiro explora diversas tonalidades nunha afinación típica do século XVII, resultando especialmente problemáticas algunhas delas (por culpa da “quinta do lobo”). Logo axusta a afinación segundo o modelo que, segundo el, empregou Bach no Das Wohltemperirte Clavier e volve explorar esas tonalidades para concluír que xa podemos tocar, sen medo, nas 24…
Para facerse unha idea de que notas se tocan na Sarabande (Suite en “si menor”, BWV 814), podemos usa-las partituras de J. S. Bach no IMSLP.
Copio e pego a presentación que o autor fixo para YouTube:
A normal 17th-Century harpsichord temperament is heard first: regular “1/6 comma meantone”.
A folk tune (Twinkle, twinkle, little star / A-B-C-D-E-F-G / Ah, vous dirais-je, Maman / Morgen kommt der Weihnachtsmann…) is played in the four keys of D, B, A-flat, and F major. Two of these scales are excellent, and two of them are terrible.
The sarabande from Bach’s B minor French Suite illustrates the behavior of this minor key: problems with the too-sharp D#, A#, and E# as they occur in the music. Those notes are too sharp because they were tuned for their more common use as Eb, Bb, and F… and in this style of tuning, the correct spelling of the note names matters that much.
Then, the harpsichord is retuned by moving six of the 12 notes in each octave. The adjustments are based on a drawing that Bach put on his title page of the “Well-Tempered Clavier”…which I take as his method of adjusting that normal tuning into something more flexible and beautiful.
The notes C, D, E, F, G, and A of the C major scale are retained as they were, and the other six notes F#, G#, A#, B, C#, D# (from the B major or F# major scales) are retuned.
The same compositions are then played again, to compare the change in harmonic and melodic quality.
Full detail about this is at http://www.larips.com and especially at the article “Bach’s Art of Temperament”.
This hands-on demonstration: 2007, Bradley Lehman at home. Flemish-style harpsichord built by Anne Acker. Folk song arrangement: Bradley Lehman, 2007.
Also check my other YouTube videos for examples of music played with this tuning: harpsichord and organ. Various full-length CDs are available, played by me and others variously on harpsichords, organs, and fortepianos: http://www-personal.umich.edu/~bpl/larips/recordings.html
P. S. (1 - IX - 2007): o doutor Lehman xa fixo outro vídeo con exemplos, onde se escoitan os preludios en “dó maior” e en “si maior” do WTC I. Está en “Harpsichord tuning: Well-Tempered Clavier”. Pero creo que non é adecuado como vídeo didáctico, porque se empezas por este vídeo sen coñecementos previos, podes pensar que hai que afinar cada vez que cambias de tonalidade…
