Allchopin, Ed and Noah are correct

. Xtopher is badly mistaken.

Its very Incorrect to play the pedal In Bach....
This semester i played The preludes in c minor and in d minor and i learned in a class that.. bach music cant be changed or modified with pedal, or forte or put a speed to it is just as it says..
Just make sure to have very nice phrases.
If you learned this in a class I suggest you change schools (or teachers).
In Bach’s time it was the performer’s responsibility to add dynamics and embellishments. These were never written down. This is not to say that one should not use dynamics or ornaments only because they are not there.
If you get a movie script, it will not tell you (except in its barest outlines) how to bring the lines to life. This is the responsibility of the Director and the actor playing the part. Just because such directions do not appear on the script does not mean that the actor should say his lines devoid of expression and deliver them in a monotone.
Composers started giving very specific directions about how their music should be interpreted with Mozart and Beethoven Before that they were not that fussy (although J.S. Bach, Handel and Telemann were fussy enough to write out their own ornaments – which caused much resentment amongst musicians at the time).
So dynamics are absolutely essential to Bach. But since he did not make them explicit one needs to make an informed decision about it. In fact, dynamics is the main way to phrase this prelude (Interestingly enough xtopher suggests that you use no dynamics, and yet directs one to have nice phrases. One wonders how…)
The best way to figure out the dynamics in this prelude is to play the broken chords as proper chords. The changes in harmony will tell one when to increase the tone and when to play softly (you could say that since the prelude is all built on the same figure, it is not broken into phrases – hence you must rely on the harmony).
So start very softly and build up a crescendo up to the fifth bar because
the harmony calls for it . Bar 6 decrease the tone and increase it again on bar 7. Bars 8 – 10 do a diminuendo. If you think harmonically you will see (hear) that bars 1 – 10 are one long phrase culminating (and progressing towards) on the change to the dominant on bar 11. This should give the general idea.
Alternatively, see if you can get your hands on the Czerny edition of the preludes. This is the way Beethoven played them (which is not to say that this is the way it should be played). This edition (which a lot of authorities turn their noses at) has plenty of dynamic and pedal markings, if you cannot come up with your own. Remember though, that Bach would expect you – as the performer – to come up with your own interpretation.
The pedal is also essential, but since the music is mostly polyphonic, it has to be used sparingly so as not to blur the several melodic lines. The decision on when and how to use the pedal pivots on the function of the pedal, namely, to
sustain sound. Use the pedal anytime you need to sustain sound, and this would be impossible with fingering alone.
I agree with Allchopin. The prelude in C sounds nicer with the pedal. However since you can sustain the bass line without the pedal, there is no need to use it if you don’t wish to.Glenn Gould plays it in an interesting way: he holds the left hand notes and plays the right hand very detached, almost staccato. For an extreme version, check out Jacques Loussier jazzy version of it, in which he plays it prestissimo (great fun!)

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Best wishes,
Bernhard.