Does octave mean eight

Answer 1

Strictly speaking, only the "oct" (which is the root of the word "octave") means eight. For example, an Octagon is a figure with eight sides, an octopus has eight tentacles, etc. (October was originally the eighth month of the year; however, two other months were added to our modern calendar so now, October is the tenth month and December is the twelfth month even though the root of its name means ten!)

The term "octave" refers to the distance (interval) between one note and the very next note with the same name. For example, from Middle C up to Treble C is one octave. Since there are seven different white-key notes (A, B, C, D, E, F and G) on the piano, if you go from one A to the very next A up or down the piano keyboard, it will be a span of 8 keys (inclusive).

When you play octaves on the piano, you are only playing two notes at a time. (Treble E and High E, Bass F and Low F, Middle C and Treble C, etc.) However, one octave of a scale refers to a series of 8 notes (if by scale, you mean the diatonic Major and minor scales). For example, one octave of the C Major scale would be C, D, E, F, G, A, B, C; one octave of the E natural minor scale would be E, F#, G, A, B, C, D, E; and so on.