A great musical number does more than hit the right notes, it stays with you long after the curtain falls.

But what exactly makes a musical song unforgettable?

A new study by London Theatre Direct has delved into the anatomy of a show-stopping number, analysing over 2,000 songs from 100 of the greatest musicals to uncover the secret formula behind theatre’s biggest hits.

Using Spotify’s extensive library of audio features, the study identified ten key musical characteristics – including tempo, energy levels and emotional tone – that define the most successful show tunes.

Streaming data revealed that songs such as Defying Gravity, Alexander Hamilton (Hamilton) and Seasons of Love (Rent) resonate most with audiences due to their emotional intensity, narrative significance and catchy melodies. 

Classic show tunes from Les Misérables, The Phantom of the Opera and Six also exhibit similar patterns, showing that structure and musical elements play a crucial role in a song’s longevity.

What makes a musical song unforgettable? A new study by London Theatre Direct has delved into the anatomy of a show-stopping number to uncover the secret formula

Data revealed that songs such as Defying Gravity, Alexander Hamilton (Hamilton) and Seasons of Love (Rent) resonate most with audiences due to their emotional intensity

The study identified ten key musical characteristics – including tempo, energy levels and emotional tone – that define the most successful show tunes

Classic show tunes from Les Misérables, The Phantom of the Opera and Six also exhibit similar patterns, showing that structure and musical elements play a crucial role in a song’s longevity

Many of these tracks incorporate elements of pop, rock and hip-hop, broadening their appeal beyond traditional theatre fans.

Among the standout findings was a balance between danceability—defined by factors such as tempo, rhythm stability, and beat strength—emotional depth, and orchestral richness, with minimal spoken-word elements to maintain a song’s melodic flow.

The study also found that the most-streamed musical numbers share common traits: they deliver powerful emotional highs and lows, mark pivotal narrative moments and feature catchy melodies that encourage repeated listening.

Ryan Woods, Commercial Director of London Theatre Direct, said: ‘Our research suggests there may be a formula to what makes a musical song work. 

‘We found key traits that successful songs share, but there’s no single blueprint for a hit.

‘The best musicals use structure to their advantage while delivering something unique that keeps audiences coming back.’