Thanks, Big Squeezy Accordion. You actually listed the modes in descending order if greatest usage.
The names all come from the first few words of prayers in Hebrew as chanted by cantors in the Ashkenazi tradition:
1. Ahavo Rabboh translates to A Great Love. Fregish, the less traditional but more widely used for this mode, is Yiddish, and reflects the fact that this mode sounds almost like the phrygian church mode.
2. Mi Sheberakh translates to May He Who Blessed …
3. Adonoy Molokh translates to The Lord King Reigns …
4. Mogen Ovos translates to Shield of our Ancestors. Since this mode is the least utilized in klezmer music, some authorities recognize only the other three.
The transliterations of the names of these modes reflects the Ashkenazi pronunciation of them.
A good source for more information on the modes, including alternate names, notation, audio examples and possible harmonizations is found at
https://www.ilanakravitz.com. This site, besides the section on modes, has much more information pertaining to klezmer music. Ilana Kravitz is a klezmer violinist based in the UK.
For those of you who want to get even more technical about the klezmer modes, Josh Horowitz goes into great detail about submodes (some of which have Hebrew names) and modal progressions in klezmer music. I don’t have a direct link to the article, but it’s available by searching
www.klezmershack.com. Josh Horowitz plays a nineteenth-century three-row CBA manufactured by Budowitz and also plays the tsimbl (a kind of hammered dulcimer used in klezmer music.) He is based in the USA.