Modes are just scales, and all come from the 'Mother of all Scales', the major scale. The easiest way to understand it is to imagine the scale as the clock we saw before. Here it is again:
The major scale, or Ionian Mode starts and ends at noon, or C in this case. Its intervals are TTsTTTs
The Dorian Mode starts and ends at 2 o'clock, or D in this case. Its intervals are TsTTTsT
The Phrygian Mode starts and ends at 4 o'clock, or E in this case. Its intervals are sTTTsTT.
The Lydian Mode starts and ends at 5 o'clock, or F in this case. Its intervals are TTTsTTs
The Mixolydian Mode starts and ends at 7 o'clock, or G in this case. Its intervals are TTsTTsT
The Aeolian Mode starts and ends at 9 o'clock, or A in this case. Its intervals are TsTTsTT
The Locrian Mode starts and ends at 11 o'clock, or B in this case. Its intervals are sTTsTTT
There are many scales and modes in music and all span one octave. As mentioned before, the master scale for Western music can be seen as the Major Scale and its 'scale degrees' are the standard by which others are measured. Scale degrees are numbered 1 to 7, and they represent the actual notes that are generated by the intervals. There is a lot more to it than stated here, and a few ways to name them verbally, but it's common practice to simple say the number, as in "five" or "seven" or "flat three" (the note between the 2 and 3) or "sharp four" (the note between the 4 and 5) which can also be called the "flat five". In the graph below, the top row of white blocks is the Tone Tone Semitone, Tone Tone Tone Semitone sequence we looked at on the previous page. The numbers are the scale degrees.
Reading from left to right is low to high. The rows of colored blocks show a variety of scales/modes. The top green row is the Major Scale, following exactly the scale degree numbers in the white blocks. This is the familiar sounding 'do re mi' scale. It is also a mode, the 'Ionian Mode'. The other six modes are below. They all come from the Major Scale as mentioned on the previous page. Each mode is really just the Major Scale started (and ended) on a different scale degree. Below them are the two Pentatonic scales (meaning '5 note' scales) and the so-called 'Blues Scale' which uses 6 notes. The 3rd degree of the scales determine whether they're major or minor. You can see that several scales use the flat three (b3) and they are the minor scales. This will make a bit more sense when we look at chords.
Meanwhile you can listen to how each one sounds (if you want to bother) by playing those intervals on one string — any string — of your guitar.The fretboard image above is lined up with the intervals to make it easy to try them out. Just start with any open string (which is the 'root' or 'tonic' or '1' ... same thing) then follow the colored blocks up the string to the 12th fret, which is one octave above the open string. If you play them on the E string, they will be E scales; on the A string they will be A scales, etc. The first note (1) names the scale. This, however, is just one (and the most impractical) way to play a scale on a guitar, but if you're just starting out, it's the easiest way to literally see those intervals and hear the differences.
Those aren't the only scales, there are other more exotic sounding collections of intervals, but they're all basically the same thing: an assortment of intervals that span one octave. If you've just started out, there's no reason to worry too much about scales. They're the raw ingredients of music, so it's a bit like getting hung up on the finer points of mixing oil paints when learning how to paint landscapes. You'd probably want to concentrate more on shapes and outlines to begin with. From these raw ingredients, though, come the real meat of music — chords — and they're very important. We'll have a quick look at the time elements, then we'll delve into chords.