Sequel is music sequencer software from German music software and equipment company Steinberg GmbH. It is essentially a heavily downsized and simplified version of Steinberg Cubase. It has been called a GarageBand clone as it features very similar functionality and interface as Apple's GarageBand, itself a heavily downsized version of Logic Pro, a competitor of Cubase.
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Sequel (software) Wikipedia(Text) CC BY-SA