About 60 miles north of Philadelphia, there’s a park that contains a large field of boulders that resonate when struck. These sounds can now be yours in a sample pack.

You can literally put nature, a natural sound emitted from a naturally occurring lump of minerals, into your mixes. DJ, producer and audio engineer COOLOUT recorded the boulders of the Ringing Rocks Park and is now making them available for you to use.

The sample pack features 35 loops and 150 one-shot WAVs of the rocks bell-like sounds they emit when struck. It’s something that has stumped scientists and has created tales of the supernatural, radiation effects, magnetic fields, but nothing that has been proven.

According to the VisitPhilly website a leading geologist in 1890 gathered a collection of the rocks at different pitches to play them as accompaniment to a local band. A literal ‘rock’ concert that local musicians sometimes partake in to this day.

You can download the sample pack for $6.99 from COOLOUT’s Bandcamp profile here: cooloutmusic.com/album/ringing-rocks-sample-pack