and had a very L.A. experience ... getting confronted by a random dude in the street, who was ready to rant and rave at a very high volume.

Ye and his wife were minding their own business Sunday on Melrose Place, when a bystander who seemed to come out of nowhere launched into an oddly personal tirade against KW as the couple walked back to their Range Rover.

Kanye and Bianca -- who was back to showing off her curves in a tight, body-hugging outfit --- appeared pretty alarmed by the outspoken man here .

.. who got somewhat close to them, and even blocked their path for a few moments as they were pulling out and leaving.

The guy seemed to have beef with Kanye ... yelling and repeating, "You ain't s***, boy!!!" The dude also told them they were in his territory and he kept saying things about Lucifer, the Devil and 666 while flashing some menacing hand signs.

Kanye let the guy have his say though ... he didn't drive off in a hurry -- instead cracking his window to get an earful once he was safely in the car with Bianca.

There was no physical confrontation, thankfully, but Ye seemed content with letting the man blow off steam.

Normies in L.A. are used to this sitch -- it happens all the time -- but you hardly see celebs have to deal with it ... especially someone like Kanye, who's prone to outbursts himself.

Anyway, check out the video ... sounds like aren't the source of anger here. With that said, it certainly was another eye-opening getup .

.. worthy of its own convo.