Varience in tempo?

[Shagdac]

It's amazing how much varience in tempo there can be on the same piece, but played by different pianists. Many times I'll work on a piece to get it "up to speed" so to speak, and then hear another recording of the very same piece by someone different playing it 10 times slower. How do you know the exact correct tempo? And how do you know how MUCH it can be varied without it actually being wrong? Is it just the pianists own interpretation and preference, or is there a way to know for sure, even when not marked on the piece?

Thanks for your help.
S

[Hmoll]

Huge grey area.
If you are performing a piece you will never know the precise tempo to use until 1) you play the piano you are performing on 2) you get an idea of the hall you are playing in - size accoustics, etc. 3) you know how you want to interperate the piece, 4) you establish what sound(s) you want.

[faulty_damper]

You just know by ear.  Isn't that easy?  If you hear someone else play, you can immediately tell if the tempo is either too fast or too slow.  You can just tell.  It's not rocket science.

[donjuan]

I depends on the style of the music.  I wouldn't recommend varying the tempo with accelerandos, ritardando, stringendos, etc in BACH. YUCH! you will destroy the music and the composer's intentions.  I would vary the tempo only when indications are shown.  Of course, tasteful little ornamental things can be added, so long as it is in style.  In Liszt, I like to build up something- Crescendo, RINFORZANDO, I add a FERMATA!!...wait...... ...  BLAM!! I play twice as fast and loud!  The keys gallop and the piece rounds out nicely, still following the bravura style of Liszt, but simply with an added fermata to hold the tension a little longer.
donjuan