Toadfrog: the Phrygian mode is rare, but not unknown in the English tradition..though it is incredibly common in Spain, for example. And there are also minor tunes with a variable second(eg Queen of Hearts and the Northern Lass)ie they veer between the Aeloian and Phrygian mode. I recorded an album of NW English tunes once, entitled "The Beggar Boy of the North"...the title track is a Phrygian tune.
    It's worth mentioning, of course, that not all songs end on the keynote of the scale, so assigning of tunes to modes can be very arbitrary. A tune that only consists of white notes on the piano, and ends on an E, would be a case in point. It would be a matter of opinion in some cases whether this was a Phrygian tune ending on its keynote, or a common or garden major tune ending on the third, or indeed an Aolian tune ending on the fifth. You would have to go by the "feel" of the tune to decide, and that is obviously an area where musicians might not agree.