Perhaps this is a subset of the question, "why did Bach write the 48?", but, anyway, I was thinking about this ever since the fantastic Angela Hewitt Bach concert. Could anyone put my mind at ease once and for all?

EDIT: I didn't know my title was too long... so here it is: Why Are Bach's Preludes & Fugues A Staple Of Pianists' Repertoire?"

counterpoint on piano needs a high amount of coordination between left and right hands in the fugues and the preludes need more expression. Therefore who better than to pick on Bach who is famed for his counterpoint and harmony. The 48 are in every key so demonstrates you are 'well-tempered' which was what Bach wanted to achieve when he wrote them

"Well tempered" has nothing to do with the pianist, it has to do with the tuning of the instrument. The "Well tempered" tuning system let muscians used any note in any key for the first time, and so Bach was celebrating a new tuning system, not the persolaity of the performer. the modern tuning system is very simlar and is technically called "equal temprament".

It's a huge topic - and very interesting if you like maths / physics. I won't even try to explain - do a web search!!

Hence the name,
48 preludes and fugues for well temepered klavier

no thanks I've studied that in a science of music module at uni

Similar but not the same....Bach was in all probability still using an unequal temperament (slightly) - we can't be sure, but there is some evidence that he was. The title page of the manuscript of Book I of the Preludes and Fugues has a pattern on it in Bach's handwriting, which has been interpreted as a coded description of Bach's preferred temperament - my husband has tried it out, and it works very well - but is not equal.

It is interesting to look at the pieces in their various keys - some of the "remote" ones - the ones which would have had rather sour intervals, often don't rest on nice comfortable chords, but instead keep on the move, which also helps get round the problem of having some keys in better tune than others. The 48 could then be seen as a demonstration of how to write for all keys.

In terms of the 48 being useful material for pianists - the counterpoint is wonderful training for any keyboard player - the skill needed to bring out as many as four different voices is considerable.

OH tell me about it!! I'm working on the A flat P&F from book 1 for grade 8. I have been able to play all the notes in the right order at the right speed for some time and that was hard enough but bringing out each voice in turn at the right times is just so much harder! Apart from anything else when I try to work on the "how" I'm playing rather that the "what", the "what" falls to bits! Still, every week is a slight improvement.

Having said which, the question was about why they are staple core repertoire: My answer to that would be because of sustained and consistent quality. Because they are immensely satisfying technical exercises as well as beautiful music, perfectly constructed. Because even the very best players continually find new depths and new insights. Because they are the best.

Personally I love playing Bach. Oddly, I don't enjoy listening to Bach keyboard work that much but the solo instrumental works (e.g. for flute, violin and cello), the orchestral music and the choral works, most particularly the great masses are (IMHO) amongst the finest artistic achievements of humanity: That's why Bach is core repertoire for any classical musician.

My teacher tells me that if I am to succeed in my belated quest for piano mastery then I must learn to play Bach properly. (I had thought that I could already play a lot of Bach quite well ... a dozen P&F's from the 48, a couple of French Suites, and most of the 2 and 3 part inventions ... I was just wrong!!)

The first thing I learned is that it is just as important to release each note with precision as it is to strike it correctly in the first place. I have a bad habit of "leaving my fingers behind" on the notes. There is no better music than Bach's for learning this skill

The second lesson is the importance of planning ahead - finding and mastering suitable fingerings to simultaneously give each note the right weight, hold it for the right length, and make each line clear is seriously hard work

No doubt I'll find more benefits as time goes by.

Meanwhile, the more I practice Bach, the better I play Mozart, Beethoven, Schumann adn Chopin.

Oh thank you Robodoc for your succinct answer! Btw, I also did Bach (his Sarabande & Rondeau from some partita) for my grade 8. Luckily I didn't have to do voice-leading on an unfamiliar piano. Good luck for your grade 8! What're your other pieces? I love the Poulenc Toccata from List C.

And I totally agree with you MadTom. My teacher is always chiding me for leaving an entire trail of notes in the Bach fugue I'm learning (no. 6 book 1). She calls it the "Hansel and Gretel Effect".

Thankyou: Mozart K 309 and Gershwin, Lisa

I find that practicing on a keyboard and switching to organ mode once in a while really shows up this problem as the notes don't die a way: You learn very quickly not to leave trailing fingers as the dissonances can be horrible (they're horrible on a piano too, just much quieter and so less noticeable). Interestingly I find that this mode also shows up when I'm taking the fingers off too soon.

Of course, this mode makes it completely impossible to bring just out one voice at a time so is not to be overused.

and even 5 parts in a couple of cases I believe...

Thanks for the great tip. My keyboard is in the UK, but there is a real organ here that I can use!