If it sounded like music with a wide pitch range and multiple bells playing at once, it may have been a carillon.
A carillon is a bell musical instrument, played from a keyboard. One, perhaps two, performers use their fists and feet to push down on batons and pedals. This purely mechanical action (no electronic, electric, or gnome assist here!) moves the clapper positioned inside the bell against the bell wall, striking the bell and allowing it to ring unimpeded (until the next strike).
A carillon has as few as 23 bells (two octaves for you musicians out there) and up to 77 bells in the largest carillons in the world (over six octaves). A standard carillon has 48 or 49 bells to make four octaves.
Carillon bells are special–they are not only cast to specific dimensions to approximate a pitch, but they are also tuned after they are cast to reach a specific pitch. Carillon bells match the chromatic pitches recognized in western musical systems, in other words, they match the pitches found on a piano or other common musical instrument in the western world. This precise level of tuning allows carillonists to perform a wide range of music, from arrangements of classical music, folk tunes, and popular music to original carillon compositions.
In one way, the carillon is like an organ, since it has pedals that play the lower notes. In another way, the carillon is like a piano, since the instrument is touch sensitive–the harder a carillonist strikes a baton or pedal, the louder the note will be.
Carillons originated in the Low Countries (modern-day Netherlands, Belgium, and northern France) in the late 15th and early 16th centuries. Today the Netherlands and Belgium still have the highest concentration of carillons in the world. Carillons have spread around the globe, present on every continent except Antarctica. North America boasts almost 200 instruments, most of them at universities or churches.
Many carillons feature a summer concert series. Check out your nearby carillon’s webpage to see if they offer music on a pleasant summer evening.