Wireless Frequency Bands

Ok, so I am transmitting a signal through the air, can I use just any frequency (Like the one my neighbors favorite radio station is on) to transmit my signal?

There are 2 Common Frequency Ranges for Wireless LAN's

The 2.4 GHz Band

From 2.4 to 2.5 GHz

The 5 GHz Band

From 5.725 to 5.875 GHz