Stop copying Datasheet! I bet you don't understand what I told
Take a closer look at Fig 8 (Variable Audio Oscillator , 20 Hz to 20 Khz).
The Best way to change the frequency value is to use a pot.
The cap timer value on pin 10 only determine the Frequency Range!
(Like in Fig 8. the 0.0047uF and the RA=RB=4.7K ===== 20 Hz - 20 Khz oscillator)