in this video series I plan to cover in moderate depth some of the driving concepts in today's tuning theory before I can do that however you need to know a little about standard tuning and some basic acoustics sound is waves of pressure that travel through the air the rate at which the high and the low pressures alternate is referred to as the sound's frequency note that the word frequency though often used synonymously with the word pitch actually refers directly to how frequent the pressure oscillations are frequency is measured in the unit called herz which denotes the number of oscillations per second when those high and low pressure waves make contact with our ear drum it flexes in accordance with those waves and sends that information to the brain this is where frequency immeasurable phenomenon becomes pitch. a subjective experience the pitch of a note refers to how high or low it sounds and changes in pitch a.k.a. intervals are measured in the units called cents where there are twelve hundred cents per octave pitch and frequency are related logarithmically meaning that linear changes in pitch like going up in octave are actually multiplications of frequency octave specifically are a doubling of frequency for instance from 400 to 800 herz is heard as an octave and so is from 800 herz to 1600 herz because each is a multiplication by two western music uses a collection of pitches that divides the octave into 12 equal parts 100 cents each makes all intervals multiples of 100 cents this is only one option however out of an infinite number of possible ways to choose what intervals to include in your music that is to say it is only one possible tuning among an infinite number of tunings this twelve-tone equal tuning is so ubiquitous in the West however that most musicians are unaware that it has a name and the alternatives even exist up next we dive into a fundamental concept in the world of tuning just intonation