FM Essential is a FREE synthesizer app for iPhone® and iPad®. FM Essential uses Frequency Modulation (FM) synthesis to create unique, dynamic, synthesizer sound. FM Essential features 10 preset Voices, Effects, Drum Pads, an Arpeggiator and more. Connect FM Essential to a Yamaha MX series synthesizer and unlock the magic! Get 271 total Voices and the ability to save and recall edited Voices. Unlocking is easy, just visit your local dealer and connect your iOS device to MX series synthesizer. Once downloaded to your device, the full version remains unlocked, even when disconnected from the MX!