Does Air Make Neptune Jazzy ?

I've noticed in recent years a discernable trend towards a jazzy style in popular music. This started with Nora Jones, then Michael Buble, Jamie Cullum, Josh Stone, and later, Madeleine Peyroux, Claire Teal, and others. It occurred, of course, against a backdrop of concurrent fads such as Rap, Hip-hop, etc.

Watching American Idol in the last few weeks I've noticed the trend again. Many of the contestants are singing older songs with a distinctly jazzy/bluesy flavour. Midnight Train to Georgia, I'm feelin' Good, My Funny Valentine, Steppin' Out with My Baby, are a few we heard just this week.

I got to wondering whether generational and communal astrological influences are at work here. Or is there another reason? Perhaps in the case of American Idol the singers are advised to sing these songs to avoid royalties on more modern songs ? Yet they are sung so well, and the style seems to come naturally to the contestants, so I doubt that's the reason.

What about astrological influences? Back between the mid-1940s and mid-1950s Neptune, which I'd guess has musical connections, was in the Air sign of Libra. Jazz and swing flourished then. Neptune left Libra around the time Bill Haley and a succession of others burst upon the scene with Rock and Roll. The next time Neptune hit Air was in 1999 when it entered Aquarius. Wasn't this roughly when the young jazz-influenced singers started arriving? Perhaps Neptune in Air brings the right kind of atmosphere for this style to flourish - just a thought!