It's summertime again for Gershwin fans, but weirdly enough, in Gershwin land the livin's not all that easy. Never has been, really. At the superficial level, who doesn't love Gershwin? But the way his music straddles the fences between jazz and classical – and at the demi-mondial level, between jazz and pop – has always made Americans uneasy. It's that weird, contradictory vein in the national character that wants (or thinks it does) to know what's what, where a guy stands.

As Jean-Yves Thibaudet points out in the notes to his new recording of Rhapsody in Blue, the "I Got Rhythm" Variations and the Piano Concerto in F (Decca), "Having grown up in France, Gershwin has always been a really important part of my life. He's been under-appreciated in the United States. There's still a stigma [in the classical-music world] about him being a jazz, film and cabaret composer. But he's a star in France and always has been."

Performing the Rhapsody and the Piano Concerto in the jazz-band versions by Ferde Grofe, while not new (MTT was a pioneer in the practice) or precedent-breaking, is virtually the point of Thibaudet's recording, with the Baltimore Symphony led by Marin Alsop, a trenchant American-music advocate. Advocate together these two out musicians do, dazzlingly, in what already feels like this year's gay record of the year. (Thibaudet, a far-out pianist I love in any repertoire he chooses, somehow keeps snagging that non-existent prize.) When their platter is spinning, it's all I want.

And yet, when I'm drawn into the same music, in the same versions – but in a wholly different ethos and sound-world – o

n the almost simultaneously released Gershwin by Grofe (Harmonia Mundi), the music feels, if notably less glitzy, a touch more savvy – dare I say authentic? – and, at least while it's weaving its time-warping magic, convincing. Steven Richman and his Harmonie Ensemble/New York go to the extra trouble of performing the Grofe arrangements with the same number of players the Paul Whiteman Orchestra, for which Grofe made the arrangements (writing specific players' names on each of the parts), used, with the predictable result that the music feels less "symphonic" but not less potent for being more band-sized.

More important, Richman's musicians are to the style born, none more than the late Al Gallodoro, in his late 90s when this recording was made but a young whipper-snapper in the Paul Whiteman Orchestra when these arrangements were new, and who plays alto saxophone, clarinet and bass clarinet on the CD. Hearing the famous clarinet glissando with which Rhapsody in Blue begins played by the man who played it first, and more than 10,000 times after that, brings new meaning to the word authority. Clarinetist Steven Barta's scoop for Alsop is juicier, but Gallodoro's is breath-taking.

Lincoln Mayorga has nothing approaching Thibaudet's pizzazz – or, to be fair to Thibaudet, the French pianist's huge expressive range, tonal palette, and emotional directness – in either the Rhapsody or the "I Got Rhythm" Variations, but then he also stays closer to the note values in the printed score and is a consummate ensemble musician. Mayorga has plenty of verve, but the microphone doesn't lick him the way it does Thibaudet. And if he's in ways closer to Gershwin, the comparison is not invidious to the "hotter" Thibaudet.

Where the Harmonie Ensemble's music-making really shines is in the arrangements of the eight Gershwin songs sandwiched between the Variations and the Rhapsody. They pull you so strongly into the sound world of the 1920s and the 30s that you completely lose sight of the fact that these are present-day musicians at work. As if to drive home the point – but the effect is utterly bewitching, not didactic – they play "The Yankee Doodle Blues" first straight and then in a wax recording made on a 1909 Edison Fireside phonograph. It's deliriously confounding.

What makes this more than an issue of which CD to have (neither is better, let alone "righter" than the other; avoid listening to them back-to-back and the issues disappear) is the difference in actual repertoire. The New Yorkers have the songs, but the Baltimorians offer the Piano Concerto in one of its most convincing performances to date. The truth is, I've never cared much for the piece, and felt my prejudice nicely confirmed until Thibaudet and Alsop leaned into its wonderful middle movement, and all my reservations melted away. The thrill of conversion never wears off.

In project after project, from Bill Evans to Duke Ellington to "movie music" and beyond, Thibaudet has proved that he's not "crossing over" into a side repertoire, but meeting other music at depth. The sparkle and polish – and delicacy and exoticism – of his playing are just icing on a rich American cake.