MIDI is a protocol that has been around for 35 years. Yes, it is a language. You can play an instrument and never address MIDI. The depth of your knowledge about MIDI is really something you have to decide for yourself.

Don’t feel bad, those who program computers and create their own software are given all the tools they need to build such software in the Data List Booklet. The “Parameter Change”, “Bulk” and other coded messages (Sysex or System Exclusive messages) found therein are not essential to play and enjoy the instrument. They can enhance the experience, but are not essential to achieve enjoyment.

If incomprehensible to you, I guess, naturally, you’d think Yamaha should explain it all to you. But that’s probably not really their responsibility... they build fabulous acoustic pianos without any manuals concerning “how to play” nor any instructions on how to build one! Lol.

While a complex “Parameter Change” Message can manipulate the deeper functions of the synth engine. As a performing musician you are typically not making those types of changes in real-time to the instrument. The types of changes you are most likely to make during a musical performance are categorized as “Control Change” messages.

Parameter Change - used in constructing how an instrument is built and behaves.
Control Change - used in the musical performance on the instrument.

Example, a “Parameter Change” might change the basic size or shape of an instrument, while actually performing the instrument that’s not a realistic concern. Control Changes are musician controls... things musicians would realistically be concerned with changing while playing.

Parameter Changes could refine a trombone into a trumpet or change it to a tuba.
Control Change messages would be more specific and targeted to help you perform the selected instrument.

“LFO Speed” is something as a musician you might like to have real time control over. A Low Frequency Oscillator is a fancy name for a device that concentrates on the subtle variance and movement required in music making. Rather than an oscillator used to recreate musical pitched vibrations, it concentrates on the slower, subtle movements — at speeds we would identify as Rates... slow or Low rates.

Pitch Modulation, Filter Modulation and Amplitude Modulation are technical terms, musician terminology would be “vibrato”, “wah-wah” and “tremolo”, respectively. While Parameter Change messages would be used to create/construct a situation that will mimic a particular class of instrument (used by the programmer), the manipulation of the Depth and application of when/where to perform this musical gesture is handled by the musician and the Control Change message. Typically applied in real-time, by the performer.

Translation: you don’t really construct the instrument when performing. In general, the Control Change (cc) messages are musician controls, designed for real time manipulation; the Parameter Change (Sysex) messages are more about designing how the instrument will behave. You don’t change the shape of the instrument while playing it.

Okay, that said,,, we are dealing with Synthesizers... the above applies when building or recreating acoustic instrument behavior. Synthesizers can and do go beyond that. No argument there... but I point out the above just so we know the ground rules — if trying to recreate familiar musical tones and behaviors, you must understand the premise on which the system is based.

Do not just jump into System Exclusive data until you’re ready.

LFO Speed is a parameter that you have direct access to... in particular, musicially use of the LFO to do “vibrato” is most likely, you have the ability to apply the LFO with a Slider and control the Speed with another Slider. The MW is found on many keyboards simply to apply this low frequency oscillation... on the reface you can access both Speed and increase Depth (apply) in real time... via real-time touch parameters.

Thanks for the (lengthy) reply. I guess i didnt stipulate my question precisely. I want to learn! Thats really the only reason i ask questions in the first place. LOL. But in all seriousness, can those sysex related parameters be mapped to an external midi controller? You didnt say they werent but Im still not sure. Id like to know so i can purchase the right midi controller/keyboard. Id like to map a number of different parameters to knobs on a controller so i can avoid menu diving for live performances with the DX. I produce EDM music--so i need to modulate all the time. Thanks.

So if you got anything from my answer, when looking in the Data List Booklet, you want to concentrate on Control Change messages as outlined on Page 8.