The wester music has 12 notes today.
Use # to indicate that we’re ascending. Conversely, using b to indicate that we’re descending.
From a C to higher or lower C, it calls a register(c3 – > c4 = 3rd register). Also, C to the next higher or lower C calls octave.
C4 = 4th register = middle C
G6 means a particular G in the C6 – > C7
A4 = 440HZ
standard tuning makes musicians play together and sound good
whole step > half step > microtones
12-TET is one tuning system
A#4 = A4 * (1.0594630943)^1
1.0594630943 ^ 12 = 2