Dotted note note is used less frequently than the dotted note. Typically, as in the example to the right, it is followed by a note whose duration is one-quarter the length of the basic note value, completing the next higher note value. Before the mid 18th century, double dots were not used. Until then, in some circumstances, single dots could mean double dots. In a French overture (and sometimes other Baroque music), notes written as dotted notes are often interpreted to mean double-dotted notes, and the following note is commensurately shortened; see Historically informed performance. A triple-dotted note is a note with
Musical note number (and 69 is the number of semitones between C (note 0) and A). And in the opposite direction, to obtain the frequency from a MIDI note "p", the formula is defined as: For notes in an A440 equal temperament, this formula delivers the standard MIDI note number ("p"). Any other frequencies fill the space between the whole numbers evenly. This lets MIDI instruments be tuned accurately in any microtuning scale, including non-western traditional tunings. Music notation systems have used letters of the alphabet for centuries. The 6th-century philosopher Boethius is known to have used the first fourteen letters of