Common and Jennifer Hudson are talking about a powerful, romantic, soulful collab -- not necessarily a wedding, at this point -- but musically, he'd love to make something together.

The topic came up last night as Common pulled up at LAX, where a photog asked him about the odds of his GF and him hitting the studio anytime soon.

Common says the chances are high, but he's not willing to say exactly when -- he approaches music like relationships ... the records have to happen organically!!!

The Chicago natives have been going strong for well over a year and Common had no problem bigging up his partner ... dubbing her one of the "greatest voices of this generation" oughta score him some points this holiday season.

Common's praise echoed much of what Jennifer told us when we spoke to her in August ... they're not embellishing their union for the public eye, but they're not dodging the PDA moments either.

It's not like Common can really overhype his woman -- Jennifer is the youngest woman to earn EGOT status, and he's just a Tony away from joining that elite status.

They're arguably the most critically acclaimed couple of all time!!!