Tequila, fresh OJ, and grenadine that sinks to create the sunrise — the Eagles made it famous in 1972.
The modern Tequila Sunrise was created in 1972 at the Trident restaurant in Sausalito, California by bartenders Bobby Lozoff and Billy Rice. The Eagles were regular customers; they liked the drink enough to take it on tour, and the Rolling Stones drank them on their 1972 US tour. The 1973 Eagles song 'Tequila Sunrise' cemented the drink's fame.
The grenadine trick — pouring it last and letting it sink — works because grenadine is made from pomegranate juice and sugar, giving it a higher density than orange juice. Real grenadine (Monin, Small Hand Foods, or homemade) is made from actual pomegranates and tastes completely different from the neon-red artificial syrup that most bars use. The difference is enormous.
Pour the grenadine first (it goes to the bottom), then add ice, tequila, and orange juice. The gradient appears in reverse.
Replace grenadine with strawberry purée or strawberry liqueur. Red at the bottom, orange above, strawberry throughout.
Replace half the orange juice with mango juice. The mango adds a tropical sweetness that suits tequila perfectly.