tempo The tempo of the music that the audio file contains, in beats per minute. Declarationvar tempo: NSNumber? { get set } See AlsoDescribing musicalbumartistaudioChannelCountaudioEncodingApplicationaudioSampleRateaudioTrackNumbercomposerkeySignaturelyricistmusicalGenrerecordingDatetimeSignaturegeneralMIDISequencemusicalInstrumentCategorymusicalInstrumentName