I think it was 1982, I wrote a paper for a course on technology and society. One of my sources was Alvin Toffler’s The Third Wave. The book makes a number of predictions for a post industrial world and was the primary source for my conclusion. (This scan shows a draft printed on continuous feed fan-fold “computer paper” by a line printer capable of only upper case letters! You can even see the holes on the left edge where the printer feed mechanism engaged the paper) Reading this 37 years later, it seems to describe the Internet, Spotify and SoundCloud!
The media will become “de-massified’ according to Alvin Toffler in post industrial society. No longer will single radio stations broadcast to thousands of anonymous listeners hungry for entertainment. Developments like cable communications will personalize listening even more than recordings have. Instead of collecting vinyl disks, listeners will be able to dial up select recordings through their cable system from a central library according to their own tastes. It is even possible that contributions to the central libraries may be made by members of the community.
I am getting tired of deriving formulas for converting various MIDI data to real time. At the moment I’m wanting to make a standard MIDI file (SMF) to CSound .sco conversion utility. (Yes, I know there already is one) The most significant part of the task is to come up with some code that takes the time signature, tempo, and timing data and converts it to clock time (in seconds)
So here we go, with an attempt of memorializing this once and for all!
MIDI Division is the number of delta-times per quarter note. I’m calling the units of division [ticks/quarter-note]
MIDI Tempo is specified in [microsecond/quarter-note]
A MIDI quarter-note is 24 MIDI-clocks. (clocks are not ticks. Clocks are not delta-times)
Some quantities comprising a MIDI time signature (we don’t need this for the problem at hand but, while I’m documenting this stuff, I’ll include it): numerator (beats-per-bar), denominator – as a negative power of two, number of MIDI-clocks per metronome click [MIDI-clocks/beat] and number of 32nd notes per MIDI quarter (this last number I’m assuming is always constant equal to eight.
So, to convert a quantity of MIDI delta-times to seconds: