Yamaha DD-55 Owner's Manual - Page 21

MIDI Functions The MIDI IN and MIDI OUT terminals, located on the DD-55's right side panel, offer broadened musical possibilities through use of MIDI. What is MIDI? What can you do with MIDI? And how can you use MIDI with the DD-55? Here are some answers to those questions... What's MIDI? No doubt you have heard the terms "acoustic instrument" and "digital instrument." In the world today, these are the two main categories of instruments. Let's consider an acoustic piano and a classical guitar as representative acoustic instruments. With the piano, you strike a key, and a hammer inside hits some strings and plays a note. With the guitar, you directly pluck a string and the note sounds. But how does a digital instrument go about playing a note? ● Acoustic guitar note production Sampling Note ● Digital instrument note production Tone Generator (Electronic circuit) Sampling Note Pluck a string and the body resonates the sound. Playing the pads Based on playing information from the pads and pedals, a sampling note stored in the tone generator is played through the speakers. As shown in the illustration above, in an electronic instrument the sampling note (previously recorded note) stored in the tone generator section (electronic circuit) is played based on information received from the pads and pedals. So then what is the information from the pads and pedals that becomes the basis for note production? For example, let's say you play a "C" quarter note using the grand piano sound on the keyboard. Unlike an acoustic instrument that puts out a resonated note, the electronic instrument puts out information from the keyboard such as with what voice, with which key, about how strong, when was it pressed and when was it released. Then each piece of information is changed into a number value and sent to the tone generator. Using these numbers as a basis, the tone generator plays the stored sampling note. ● Example of Keyboard Information Voice number (with what voice) Note number (with which key) Note on (when was it pressed) and note off (when was it released) Velocity (about how strong) 01 (grand piano) 60 (C3) Timing expressed numerically (quarter note) 120 (strong) 21