Actually, I don't use quite the same means to get my tab as KenH does. I find out what the starting note of the key is not the starting note of the tune. Let's say the key signature is G, I number my G's as 3 or 10 depending on their position (low to high) on the staff, then I find out what the resolving note of the music is. If it ends on 1 or 8, I play it in Aeolian, if it ends on a 4, I'll play it in Dorian. But I have many Aeolian songs that don't begin on 3. In fact none of my Aeolian songs begin on 3.Artsa Alinu starts 1 ends 1Dodi Li starts 1 ends 1Donna Donna starts 5 ends 1Erev Shel Shoshanim 1 to 1The Foggy Dew 5 to 1HaTikvah 1 to 1Jerusalem of Gold 5 to 1The Parting Glass 5 to 1Peat Bog Soldier 1 to 1Shalom Chaverin 5 to 1The Star of the County Down 0 to 1Black is the Color 1 to 1I really never pay attention to the starting note of a song as through the years singers have started higher or lower sort of at their choice, but you usually don't change the modal tuning at whim. So if you want to just take a folk song book that has a lot of tunes in it that you know, all you have to do to be able to decide what mode you need is to know what key the tune is written in and give that note the number 3 and go up or down from there. If it ends on a 3 or 10 it's in Ionian and can be tuned DAA . If the song ends on a 1 or 8, DAC would be the tuning/Aeolian/1-5-7. If it ends on 4, Dorian, DAG, 1-5-4. And if it end on 0 Mixolydian with the flatted 7th note at the 6th fret.If, however, you want to play in DAd using a tab for a major pattern tune (Ionian) you need to subtract 3 to get started on the zero. DAA/3 is DAd 0. Notes below DAA/3 can be played on the MIDDLE string at the same place DAA/2 is DAd/2 DAA/1 is DAd/1 and DAA/0 is DAd/0 However, DAA/9 is DAd/6+. It's fairly simple to find what mode you need for traditional types of folk songs. As for Phrygian, Lydian and Locrian, unless you want to write tunes in these modes, you're not going to be finding very many tunes all ready in them. One author of an instructional book I have that teaches modes had to write his own tunes to demonstrate them. Ken Hulme said:
Aeolian Notes
A Mode is an octave (8 note) scale in diatonic music. Tonal music uses a 12 step scale.Modes are divided into two groups major and minor. Ionian mode is the Major Scale in tonal music - no sharps or flats. Aeolian mode is the Natural Minor Scale in tonal music. Compared to Ionian, its 3rd, 6th, and 7th notes are flatted.Modes are defined by the pattern of Whole steps and Half steps in the scale, not by the actual pitches (notes) used.Aeolian Mode (W-H-W-W-H-W-W)Aeolian mode is referred to by many people as the minor key. Aeolian intervals create the same feel as many modern blues songs. Songs in Aeolian mode have a strong sense of sadness. The final note of an Aeolian scale feels resolved in a completely different sense than the Ionian. If Dorian mode sounds melancholy Aeolian mode reeks of despair.Dorian Mode (W-H-W-W-W-H-W)Dorian is most commonly heard in Celtic music and early American folk songs derived from Irish melodies. Dorian mode sounds a little melancholy because the final note (re) doesn't quite resolve itself. The song may be over, but the singer is still unsettled.Each mode starts on a different fret:Mixolydian starts at the Open and 7th fretAeolian starts at the 1st and 8th fretLocrian starts at the 2nd and 9th fretIonian starts at the 3rd and 10th fretDorian starts at the 4th and 11th fretPhrygian starts at the 5th and 12th fretLydian starts at the 6th and 13th fretThe Keynote (A-G) depends on the note to which the open Bass string of the dulcimer is tuned. Each mode has a "traditional Keynote" (low 'do') associated with it:Aeolian A traditional tuning AEGLocrian B typical tuning Bb F GIonian C traditional tuning CGGDorian D traditional tuning DAGPhrygian E typical dulcimer tuning E Bb GLydian F typical dulcimer tuning F E BbMixolydian G traditional tuning GDgSince so many people have become D-sensitized (all puns intended) to the traditional keynotes of the Modes, here are the key of D Modal tunings:Ionian.........DAA...1-5-5Locrian.......DAB...1-5-6Aeolian.......DAC...1-5-7Mixolydian...DAd...1-5-8Lydian........DAE...1-5-2Phrygian......DAF...1-5-3Dorian........DAG...1-5-4Only Locrian and Dorian are left in their traditional keynotes.If youre tuned in Ionian mode and are tabbing out a song... If the first note is on the third fret, but the last note is on 1 or 8 then play the music in Aeolian Mode. If the first note is on the third fret but the last note is a 4, play it in Dorian.