MMario, what is the 2nd most popular mode depends on where you get your tunes. I think for a general run of instrumental tunes minor mode would be 2nd, but for the 700 or so English traditional vocal tunes of the late 19th and early 20th century that I've coded, minor/aeolian is in 4th place. For the 700+ traditional Irish vocal tunes in Huntington and Herrmann's 'Sam Henry's Songs of the People' (coded at the end of the book) minor/Aeolian is down to 8th place. I've added some more tunes to my file (and have about 1000 more coded, but not yet formatted to read into my program) and the mode count is now at 165.