There is no absolute limit on frequencies. The frequencies can be almost arbitrarily small or big.

There is no absolute limit on frequencies. The frequencies can be almost arbitrarily small or big.

There is no absolute limit on frequencies. The frequencies can be almost arbitrarily small or big.

There is no absolute limit on frequencies. The frequencies can be almost arbitrarily small or big.

no

Unless you have access to the original recordings with a separate vocal track it is impossible to remove the vocals as they become mixed into a single track with all the other instruments. Depending on the individual track you may be able to reduce them with an equaliser by fading down the mid frequencies but this will also reduce the other instruments too.

The tone frequencies, are selected such that harmonics and intermodulation products will not cause an unreliable signal. No frequency is a multiple of another, the difference between any two frequencies does not equal any of the frequencies, and the sum of any two frequencies does not equal any of the frequencies.

Airband, a group of frequencies in the VHF radio spectrum, uses the frequencies between 108 and 137 megahertz. A license is required to operate airband equipment.