Mode Summary

The modern Major Scale for all keys is based on the Ionian Mode with an interval structure of T-T-S-T-T-T-S

The modern natural Minor Scale for all keys is based on the Aeolian Mode with an interval structure of T-S-T-T-S-T-T

The most usual 'modal' mode is Mixolydian with an interval structure of T-T-S-T-T-S-T

All modern keys can be converted to modes by applying the interval structure of that mode from the starting note (tonic)

There are other modes, some of which are invented and are not included here.
A common traditional mode (and one of the oldest) is the 'pentatonic' mode which only has 5 notes in the scale.
The major Pentatonic scale starting on C is:

	I		II		III		IV		V		VI
		Tone		Tone		Tone+Semitone		Tone		Tone+Semitone
Note	C		D		E		G		A		C

The Pentatonic Minor has intervals of [T+S]-T-T-[T+S]-T.

Other scales/modes are:

	I		II		III		IV		V		VI		VII		VIII
Hungarian	C	Tone	D	Semitone	D#	Tone+Semitone	F#	Semitone	G	Semitone	G#	Tone+Semitone	B	Semitone	C
Neapolitan	C	Semitone	C#	Tone	D#	Tone	F	Tone	G	Tone	A	Tone	B	Semitone	C