While going about my daily routine/business, a mainstream song was playing, and I thought to myself "this reminds me of a song from Xenosaga Freaks". I forgot the lyrics (of the English language song) later that night (so I didn't have anything to search with) but a Japanese user already figured it out: "estrellita" is more-or-less an arrange of "
Love In The First Degree" by 80s group "Bananarama".
estrellita has some additions/embellishments compared to the original but the overall song structure and melody is basically the same. The other songs don't ring any bells, for now at least.
Also, a small section of Yuzo Koshiro's "Dancing Heart" from "Misty Blue" seems to have a familiar sounding riff (begins at about 0:57) - to me at least.
See also
Hanjuku Hero 4 -The 7 Heroes- ~Sound Collection~ for random arranges of mainstream songs.