Can someone explain what the ‘musical modes’ are about? Mixolydian, Aolian, Phrygian, etc..
I know they have something to do with the scales used, but what is the difference between a tune in key x, and a tune in mode x?
Run a search for “modes” or “modal.” We’ve been over this many times. Take what you find with a grain of salt, of course.
Yep, it’s a big topic. Here are a couple of threads:
http://chiffboard.mati.ca/viewtopic.php?t=48511
http://chiffboard.mati.ca/viewtopic.php?t=49053
Also this Wikipedia article:
http://en.wikipedia.org/wiki/Musical_mode
In a nutshell, a mode is a scale that starts and ends on one of the notes (or “scale degrees”) of the normal major scale.
The mode that starts on the 1st note of the major scale is the Ionian mode.
The mode that starts on the 2nd note of the major scale is the Dorian mode.
The mode that starts on the 5th note of the major scale is the Mixolydian mode.
The mode that starts on the 6th note of the major scale is the Aeolian mode.
These are the 4 modes that you mostly hear in ITM. The others are not much used. For reference, they are: Phrygian (3rd note), Lydian (4th note), Locrian (7th note).
In classical music terms of Major and Minor, Ionian is the same as Major and Aeolian is the same as Natural Minor.
Also, the Dorian mode has a minor sound, and the Mixolydian mode has a major sound. So sometimes Ionian and Mixolydian are both referred to as Major modes, and Aeolian and Dorian both as minor modes. In this context, I sometimes use the terms “major-ish” and “minor-ish”
This information is easily applied on a D whistle, flute, or chanter, where the natural scale is D major.
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Start on bottom D, and play a one octave D Major scale up and back down. Voilà, you just played a D Ionian scale: D E F# G A B c# d.
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Now start on the bottom E - the 2nd note of the D Major scale. Play the same scale notes as above, but from E up to e and back down. Voilà, you just played an E Dorian scale: E F# G A B c# d e.
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Start on an A - the 5th note of the D Major scale. Play the same scale notes from A to high a. That’s the A Mixolydian mode: A B c# d e f# g a.
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Start on an B - the 6th note of the D Major scale. Play the same scale notes from B to high b. That’s the B Aeolian mode: B c# d e f# g a b.
That’s basically all there is to it.
You can do the same thing with any scale. For example, play a G Major scale: G A B c-nat d e f# g. Now play those scale notes starting on the 2nd note A: A B c-nat d e f# g a. That’s the A Dorian mode.
Each mode has a distinctive sound. So after a while, you get to the point where you can identify the different modes by how they sound.
Another trick: The Mixolydian scale is the equivalent of a Major scale with the 7th note flattened by a half-step (b7). And the Dorian scale is the Natural Minor scale with the 6th note sharpened by a half-step (#6). So you can listen for these distinctive notes to tell the difference.
When you talk about the “key” of a tune, you mean the tonal center of the tune. In casual usage, saying “key of X” is usually shorthand for “X Major”. But in classical music it could be Major or Minor, and in ITM it could be any one of the modes. So it’s usually good to be explicit and say key of “G Major”, “D Mixolydian”, or whatever it is.
Final point: All the modes that are based on a particular major scale can be considered to be a “family” of modes. For example, the modes I described above are the “D Major family” of modes. And interestingly, all the modes in a family share the same key signature as their parent. Since D Major has a key signature of 2 sharps (F# and C#), the E Dorian, A Mixolydian, and B Aeolian/Minor also have 2 sharps as their key signatures.
Hope that helps … grains of salt and all … 
THANK YOU for writing a LUCID description!! Are you up this weekend???
You’re welcome! I usually think of modes in terms of the white keys on the piano and the C Major family of modes. But it occurred to me that makes sense for ITM wind players to think in terms of the D Major family, because that’s the natural scale of our instruments.
Just looked at your site; I’ll have to explore it when I get a moment. Off to ride my bike
Excellent post, Mr Guru! There are one or two tunes that work out in Lydian mode (if you play 'em the same as me 
), namely the Turnip Jig (aka Paudy Scully’s Slide) and Cronin’s Hornpipe. My version of Gillan’s Apples is also in Lydian mode. Sometimes a tune seems to “fit” more than one mode because some notes of the scale are missing. Likewise, some are just pentatonic. I’m not sure how they fit into modes. I like to tell people that I can play the tune of the song “Dirty Old Town” in three different positions on a diatonic harmonica (e.g. if you use a D harp it can be played in D, G or A without note-bending). Amazing Grace is another such, as is Auld Lang Syne.
Thank you guys - I did do some looking around but asked here because all I found was detail and technical stuff which didn’t do a good job of explaining essentially what the concept was and how it fitted into our understanding of music.
Thanks again 
That’s excellent, Marcus. It’s perfectly consistent with what I wrote, and it reinforces and expands my description. And it covers the other modes and gapped scales that Steve mentioned above. Thank you for the link!
I suppose, but I’m not too keen on all those “celtic feel” references, and I’d definitely argue with him that a tune with both Cs and C#s is not a modal tune. I can play any truly modal tune on a diatonic harmonica without bending. But I need a chromatic harp for Jenny’s Wedding. Still, good stuff though.
I think it was Breandan Breathnach who coined the term “inflection” for the idea of notes alternating between two pitches, the notes being called “inflected” notes. These notes on normally-pitched Irish instruments are C and F.
These often alternate so often that one is hard-pressed to decide which key a tune is in.
There are keys/modes, and there are scales. The Kesh Jig and Jimmy Ward’s Jig are both in the key of G, in that most guitarists would play a G chord in the first bar. But, they use different scales: Kesh lacks the note C (in other words has no 4th degree) and Ward’s lack the note F (has no 7th degree). Interesting and perhaps significant that these are the very notes most often “inflected”.