Over our C minor chord, we get a triplet figure of all B♭s, making the chord a C minor 7. This is followed by the use of a passing tone (Ab) to get from the 7th to the 5th. Finally, over the B♭, we have an F (the fifth of the chord), moving to a G (the 13th, another tension).
We all know that sound is a wave. The curves and spikes of our friend the “waveform” are a graphic representation of that wave’s action, traveling physically through air. If I clap my hands and record it into my DAW, the peaks and troughs on the screen represent the fluctuating changes in air pressure that cause the sensory phenomenon we call sound. These ripples of pressure in the air make our eardrums vibrate, so we can hear that sound.