Tokøta from Mastering.com breaks down Logic Pro's EFM1 synth and how frequency modulation actually works. A modulator oscillator shapes the tone of a carrier oscillator, and that relationship is what produces FM's signature metallic, bell-like, plucky character.
The walkthrough covers harmonics, fine tune, modulator pitch, FM depth, and how an envelope on the modulator creates swelling or evolving tones. Glide, sub oscillator blending, stereo detune, and LFO routing to pitch or FM depth round out the sound-shaping options.
A full patch gets built from scratch: harmonics pushed up, an envelope added for swell, vibrato and stereo detune layered in to thicken the tone.
The randomize function gets a dedicated demo. Set a randomization percentage and repeatedly hit randomize to mutate your current settings into new patches, a fast way to stumble into sounds you wouldn't have programmed intentionally.