Part of the big complex of La Villette (where you can also see the Cité des Sciences, Parc de La Villette, concert halls, etc.), the Cité de la Musique is home to a permanent museum as well as temporary expositions.
The permanent museum presents a large collection of music instruments used in Europe since the 17th century till nowadays. Although they are in showcases, you can listen to the audio recordings with the audio guide (which you can borrow for free at the entrance). With this guide, you can just stroll through the 5 halls of the museum, listening to sounds of Italian 17th century harpsichords, recollections of great operas or even sounds electronic synthesisers which deeply changed the music during the 20th century.
For more information, the museum also presents documentaries, and socio-historic explanations are available on the audio guide to help you understand the evolution of music in its context (geographic and politic). The same explanations, but more funny, are also available for kids. You should count two hours to visit the whole, very nice, museum, which combines learning with entertainment. It is also interesting for lay persons who will discover very particular sounds and… surprising instruments!
Don’t miss the last hall, dedicated to world music, in which you will see incredible videos (like these African women playing rhythms in a river). These videos will once again prove that music is a major cultural element with unchanging values (solidarity, sharing), no matter what country or century you’re in.