Melodic 2nds - Distance from a white key to the next white key, either up and down the keyboard. On the staff melodic 2nds go from line to space and vice versa.
Melodic 3rds - When you skip a white key that is a melodic 3rd. On the staff it goes from space to space or from line to line.
Melodic 4ths - Skipping 2 white keys, on the staff melodic 4ths go from line to space or space to line.
Melodic 5ths - Skipping 3 white keys, on the staff melodic 5ths go from space to space or from line to line.
Melodic 6ths - Skipping 4 white keys, on the staff it goes from line to space or space to line.
Melodic 7ths - Skipping 5 white keys, on the staff it goes from space to space or,line to line.
An octave is when you skip 6 white keys. For example from C to C, E to E or G to G. On the staff an octave goes from line to space or space to line.

