As expected, R.E.M.'s latest is a Monster out of the box, debuting at No. 1 on the pop chart after weeks of prerelease hype and incessant airings of the first video, ''What's the Frequency, Kenneth?'' Having sold nearly 7 million copies of the more subdued Automatic for the People and Out of Time without touring, the quartet is expected to match those figures easily, thanks to their first tour in five years. The tour, in fact, may even rival the popularity of Barbra Streisand's extravaganza, which seems to have lost some glitter: Her double-CD live set debuts at No. 10, outdistanced even by satanic speed-metal freaks Slayer.