piano keys	distance in half tones	name written	name spoken	interval referring to C	interval symbol
	0	C	C	tonic	1
	1	C# / Db	C sharp / D flat	minor second	b2
	2	D	D	major second	2
	3	D# / Eb	D sharp / E flat	minor third	b3
	4	E	E	major third	3
	5	F	F	perfect fourth	4
	6	F# / Gb	F sharp / G flat	tritone	#4 / b5
	7	G	G	perfect fifth	5
	8	G# / Ab	G sharp / A flat	minor sixth	b6
	9	A	A	major sixth	6
	10	A# / Bb	A sharp / B flat	minor seventh	b7
	11	B	B	major seventh	7
	12	C	C	octave	8