Teaching Notes for Prelude and Fugue in Bb - Grade 8 ABRSM Piano 2023-2024 A1

Prelude and Fugue in Bb BWV 866
J. S. Bach 

Teaching Notes

Prelude
This piece should be performed in a rather improvisatory style, with flexible changes of tempo. For example, the chordal passages from bar 11, are traditionally performed "Adagio" with the other demisemiquavers more of a technically impressive "Presto". In fact, the chords of bar 11 are actually marked "Adagio" in the copy of one of Bach's pupils.

In the opening bars, don't think of the two hands as being a duet, but rather one voice, thus detaching and shortening the LH quavers at the beginning so as not to overlap the following demisemiquavers. Likewise, the scalic passages such as those starting from bar 3, should flow between the hands.

As with much Baroque music, there are no written dynamics, but extra credit will be given for creative additions. For example, the first half of bar 6, is an exact repeat of the last half of bar 5 and so an echo effect here would be effective and stylistic.

Care needs to taken with the exact length of the tied notes in bars 11, 13, 16, 18 and 20. In each case, any other notes that were sounding at the beginning of the tied pairs, should be released, allowing the end of the tied pairs to "sing" before the runs break away. For example, in bar 11, release all the notes of the final chord except the top F, then listen to this upper note for a brief moment as a "solo voice" before commencing the G at the beginning of the "Presto" scale.

Fugue

A good idea, before starting to practise this piece, would be to mark every instance where the opening theme is repeated, as this part should always be the dominant voice throughout. That is:

Bar 1: RH (Obviously)

Bar 5: LH

Bar 9: LH

Bar 13: RH

Bar 22: Lower RH

Bar 26: LH

Bar 35: Upper LH

Bar 37: RH

Bar 41: Lower RH

In each case the theme starts on the 2nd quaver of the bar and your tonal control should reflect this in announcing the entry of a new voice 

However there are other instances where this opening theme is inverted, such as bars 19 - 21 and 30 - 34 and would benefit from a similar bring out of the melodic line.

At the end of the main theme, there is a two bar run of semiquavers which contain a repetition of the melodic material half way through. As such, some dynamic shaping, that is to make the second half an echo of the first would gain some creative credit in the exam. It will be noticed in the performance above that the two halves are divided by a slight break of breath in the phrasing even with some possibly controversial rubato easing of the tempo at the end of the first half. If you are going to adopt this styling, be sure to make the phrasing /  changes exactly on the 2nd quaver (3rd semiquaver) of the bar.

Other potential echo effects from repeated semiquaver patterns can be found in bars: 7-8; 11-12; 15-16; 17-18; 24-25; 28-29; 39-40; 43-44; 45-46.

In bars 33 and 34, be careful to hold the lower crotchet on the last beat its full length, that is overlapping the final quaver.

Some careful finger work will be needed in bars 45 and 46, where the middle part will be alternating between the two hands sometimes just for a note at a time as indicated by the up / down brackets in the ABRSM edition, although other fingerings are possible. In any case, learn one finger pattern thoroughly to commit to muscle memory.