Modern Records on sleeve, Crown on label.
Runout is Modern Records (MMLP), not Crown (CLP)

From the liner notes

"Here is giant jazz played by giant jazzmen, masked to conceal their startling identity, blowing with the enormous fervor and rushing push you've always wished for and seldom found on good jazz albums.
Ah, the problem of cold business! Here was a recording session like you'd always dreamed about, and yet how to give it to the people without making some of the companies that held the contracts of these jazz giants feel bad? The answer was a masquerade, a masquerade party!
What other more splendid way to bring together such a galaxy of big jazz names? And why not invite the teeming body of their adulating fans? Admit them all! And so you hear a great, rolling throng at hand, cheering their musical heroes on to greater and greater heights!
The names of the mysterious swingers behind those concealing masks would read like a convention of the elite of the modern jazz world. Listening in awe to this amazing, no-holds-barred music, one asks one's self, 'Must not this clever crew include:

Jimmy Giuffre? Wardell Gray? Teddy Edwards?
Isn't that Howard McGhee? Shelly Manne?
Vido Musso? Ben Webster? Benny Carter?
Charlie Parker? Shorty Rogers?

And aren't there others?' ...but why go on? One can only guess..."