These 23 songs every Broadway fan knows could actually help fight dementia.

Back in 2013, researchers in the U.S. stumbled upon a novel new treatment for dementia patients: listening to show tunes. Seriously.

“West Side Story.” Photo by Fred Fehl/Wikimedia Commons.

A study of nursing home patients found that residents who sang show tunes — specifically from “Oklahoma!” “The Wizard of Oz,” and “The Sound of Music” — demonstrated increased mental performance, according to a report in the New York Daily News:

“Researchers working with elderly residents at an East Coast care home found in a four-month long study … that people who sang their favorite songs showed a marked improvement compared to those who just listened.”

A similar study in Finland, cited in The Guardian, demonstrated that singing not only helped dementia patients feel better and focus, but actually improved certain types of memory as well.

Even better? There are tons of classic show tunes specifically about remembering.

Here are 23 tunes every Broadway fan needs to memorize for the day when it’s not so easy to remember. It’ll help to start brushing up now.

1. The one about remembering the good old days.