Cardioid microphones have a high gain in the front and sides of the microphone but have a low gain in the back of the microphone. The directional sound pick-up pattern of a cardioid microphone has a heart-like shape, where the microphone gets its name from. You can use cardioid microphones in applications where sound must be acquired from the front and sides but not the back. One possible illustration of this would be a musical performance, in which a singer would be performing in the front, a band would play instruments on the sides, and viewers would be seated in the rear. It may only be necessary to record the music, the singer in the front, and the band on the side, but capturing the audience in the back will not be required. Microphones with cardioid polar patterns are useful and applicable in situations like this.