The singer made a big announcement Tuesday -- dropping the release date for her forthcoming album, "Cowboy Carter," as March 29 ... and adding a lengthy caption to describe the process that went into making this one.

She starts out by thanking everyone for blowing up her two new singles -- "Texas Hold 'Em" and "16 Carriages" -- and goes on to say she's excited to trot out this new era of hers.

Bey writes, "This album has been over five years in the making. It was born out of an experience that I had years ago where I did not feel welcomed…and it was very clear that I wasn’t. But, because of that experience, I did a deeper dive into the history of Country music and studied our rich musical archive."

She also notes she faced criticism when she first broached the country music scene -- something that was well-documented at the time with her track "Daddy Lessons."

With all that, Beyoncé says this ... "I have a few surprises on the album, and have collaborated with some brilliant artists who I deeply respect. I hope that you can hear my heart and soul, and all the love and passion that I poured into every detail and every sound."

She finishes by saying "Cowboy Carter" isn't a country album, but rather ... a Beyoncé album -- which is obviously exciting, but her suggesting some legendary acts are on this project has seriously piqued people's curiosity ... including the Swifties.

Fact is ... a Beyonce and Taylor collab would be one the biggest musical team-ups in recent memory -- and the fact that Taylor got her start in country isn't lost on anyone either.

Plus, we know T-Swift and Bey are already friendly -- having attended the other's respective movie premieres last year ... so we know for a fact they respect and support each other.

Also, remember ... music producer Killah B -- who came up with the beat for "Texas Hold 'Em" -- played coy with us when we asked him point blank if there was a possibility Taylor might appear on this record of Bey's. Worth noting ... he didn't outright deny it at the time.