YOU will hear more than enough about Zooropa, the new U2 album, over the next month or so. Such is the monstrous clout of the world's biggest band that this eclectic release, despite a minimum of advance publicity, is triggering an explosion of media fanfare and a ''gotta have it'' frenzy among fans. What is even more amazing is that Zooropa (from Polygram) comes at the height of summer, the record industry's traditional off-season. It is a reflection of total confidence, reminiscent of that band that released Sgt. Pepper for 1967's ''Summer of Love''. But is there actually substance behind the hype? There will doubtless be many detractors - mostly those for whom anything this popular just cannot be hip enough to be good. They come up against a fundamental problem, though. Zooropa is a fine album. And although much has been made of the idea that Zooropa isn't a commercial release - with nary a hit in sight - don't let that fool you. There is plenty of pretty music here. And, at this stage, a group as monumental as U2 can almost dictate what becomes a hit. Case in point, the first ''single'' Numb. This song, taken and reworked from the Achtung Baby sessions, features a spoken monotone vocal by The Edge over little more than droning - and not excessively danceable - Euro-beat. It is unlike anything U2 has done before, and a very cagey move. WHILE not a true single, merely released for radio and television play, Numb would seem calculated to draw attention to the fact that something odd is going on. And the rest of Zooropa is nothing if not odd. Produced by Brian Eno, The Edge and Flood, Zooropa takes Achtung Baby 's four good Irish boys gone Teutonic a step further. The opening title track sets off with a wash of ambient synthesisers and radio noise before Bono sings his first line, ''Zooropa . . . Vorsprung durch Technik''. This is followed by a series of similar advertising slogans before the song finally soars into more familiar U2 territory. The effect is glorious. The second track, besides its obvious hit potential, is a hybrid. Babyface sounds like something from David Bowie's Low (which Eno worked on) mixed with the feeling of Marc Bolan. Lemon, with a Mick Jagger-style falsetto vocal, projects a healthy carnality. But the interest here lies in the backing vocals from The Edge and Eno, which bear more than a passing resemblance to Talking Heads - another band with whom Eno has worked. However, U2's sound is so distinctive it can comfortably absorb other influences. But just when you thought you might have had Zooropa figured out, it throws yet another curve. The final track is the gentle, techno-pulsing The Wanderer. And the very strange thing is The Wanderer has a pseudo Country and Western lyric and is sung by the legendary Johnny Cash.