While listening to Bach's Cantata 66 (first choir)
http://imslp.info/files/imglnks/usimg/3/31/IMSLP01220-BWV0066.pdfI found what it looked like straight (bad) parallel 8ves between bass and violins (playing in unison) + trumpet! In this link, the passage in question is on the first page, mss. 7-8. The notes forming the parallelism are G# and the following A (the same thing also appears transposed later on in the score). After a "double take" at it, I realized that there was actually no mistake here, only a very clever take on the idea, which justified the ACTUAL and REAL aural feeling of parallel 8ves (actually, in contrary motion). No mistake: you can hear them AND see them... or can't you? ;-) It looks like Bach found a way of making them legal, so to speak.
Anybody up to the (small) challenge of theoretically justifying those parallel 8ves?
No prices, sorry. I'm just curious to see if some of us think along the same lines (you ol' folks out there :-)
Gianluca
I guess this forum it's been SLOOOOOOOW lately. I blame myself too for that...:-)
Anyhow, here's why I think those 8ves are... good.
1) Mss. 7-8, bass: these two measures (and others before) show a "compound line", where the first two notes of ms. 7 (B, D) resolve in ms. 8 to (lower) A and E respectively, while the G# of ms. 7 resolves to the SECOND BEAT (higher) A of ms. 8.
2) Therefore, the first (lower) A of ms. 8 in the bass is NOT the resolution for the preceding G#, but the resolution of the B. Which means that, although there's a G#-A octaves between violins and bass, they don't count, since they involve "other voices". Crazy, but true...
I can e-mail you a written-out version of the above, which will be much clearer... I hope!
G
