PINARBASI, Turkey—Ahmet Tuzer's motto could be: I rock, therefore imam.

By day, the 42-year old Muslim cleric chants the Azan—the Islamic call to prayer—from a small mosque in the coastal village of Pinarbasi, where he preaches to about 150 people. By night, he preaches the gospel of Led Zeppelin, singing about a different stairway to heaven with his four-piece rock band, FiRock, led by Mr. Tuzer and heavily tattooed metal guitarist Dogan Sakin.

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