Beyonce's Music Video Dancers SHOCKED Too -- We Had No Idea This Was Gonna Drop

Beyonce didn't just keep her new album and music videos a secret from the world -- she actually kept it from nearly EVERYONE involved in production ... even her dancers.

One of the dancers for the "Blow" video -- a girl named Morgan Hebert -- tells us, she knew she was involved in some kind of video project for the singer when they were filming in Houston in September, but she didn't know exactly what.

Morgan says it was all arranged VERY last minute. She and a few other dancers from Beyonce's Super Bowl show flew to Houston for the 2-day shoot and it was like Fort Knox. No cell phones, no pictures, nothing. She also had to sign a scary confidentiality agreement.

Morgan says she figured it was all for a music video, but didn't expect anything to be released until next year.

When she woke up today to see her video all over the Internet -- in addition to a FULL album and 16 other music videos -- Morgan says she was blown away.

Seriously impressive. These days, it's like albums leak before they're even recorded.