Before you wanted a square-wave. Now you want a 960Hz sine-wave?
A 960Hz square-wave also has the odd-numbered harmonics at 2880Hz, 4800Hz, 6720Hz, 8640Hz, 10560Hz, 12480Hz, 14400Hz, 16320hz, 18240Hz and 20160Hz. The output of a 555 oscillator is almost a square-wave. It is actually a rectangular-wave with some even-numbered harmonics added in. You can make a 555 produce a square-wave if you connect it as an inverting Schmitt trigger.
The 555 will overheat when it tries to drive an 8 ohm speaker. You must add a resistor in series with the speaker to limit the current to no more than 200mA but then the speaker will not be loud.