Singing the Beatles in the shower can help save the planet, British researchers claim.
Love Me Do has been named the perfect pop song for people trying to limit how long they spend getting washed.
Environmentalists reckon if people spent a minute less in the shower every day, it would save enough water to supply London for two to four months.
Thames Water has advised people to sing "short, water-efficient" songs lasting less than four minutes.
The Lennon and McCartney hit is No. 1 on the water company's four-minute shower challenge list.
"The reason we're asking people to sing short, water-efficient songs of four minutes or less in the shower is to help them hit the four-minute shower challenge," Thames Water's Jayne Farrin said.
Thames Water's top five shower songs were Love Me Do by the Beatles, Love Me Tender by Elvis Presley, Dance Wiv Me by Dizzee Rascal, Could It Be Magic by Take That and It's Raining Men by the Weather Girls.
Five to avoid in the shower are Stairway To Heaven by Led Zeppelin, American Pie by Don McLean, I Would Do Anything For Love by Meat Loaf, Rapper's Delight by the Sugar Hill Gang and Echoes by Pink Floyd.
The number of litres of water Britishers use every day