You can also mention for interest that your scale is actually a logarithm.
x + 12 = 880 Hz in your notation.
The reason and importance of intervals are due to the harmonic series.
Perfect 5th = 3/2 * x (or x + 7 in your notation)
Perfect 4th = 4/3 * x (or x + 5 in your notation)
The 12-note equal temperament is a little off from these ratios as a hack to allow multiple key signatures. You'll find that 3/2 ~= 12_sqrt(2)^7.
You can go into complicated chords too, and you'll still find dualities and the hormonic series behind it. A major chord is a stacked major 3rd with a minor 3rd and together they range over a perfect 5th.
x + 12 = 880 Hz in your notation.
The reason and importance of intervals are due to the harmonic series.
Perfect 5th = 3/2 * x (or x + 7 in your notation)
Perfect 4th = 4/3 * x (or x + 5 in your notation)
The 12-note equal temperament is a little off from these ratios as a hack to allow multiple key signatures. You'll find that 3/2 ~= 12_sqrt(2)^7.
You can go into complicated chords too, and you'll still find dualities and the hormonic series behind it. A major chord is a stacked major 3rd with a minor 3rd and together they range over a perfect 5th.