Here's an odd overlap: bluegrass and metal. One is acoustic old-timey folk music based on a strict traditional structure. The other is newfangled loud distorted electric guitar rock.
Polar opposites, right?
Maybe not so much.
Bluegrass grew out of early country and the folk music brought to the Appalachians by British colonists centuries ago, plus influences along the way from many other styles. Songs are typically in 3/4 or 4/4 time in a major key with standard chord progression, often structured as dance melodies. Lyrics range from spiritual themes to running moonshine, but tend to focus on rural themes, especially Appalachia.
What's harder than hard rock? METAL!!! It's not just louder, it's often more intricate with unusual time signatures, strange chord progressions, and lyrics spanning everything from epic myths to literal Satanism.
Bluegrass music tends to feature each musician in the band taking the lead and showing off their musical chops with some fast and intricate performances. Fast, clean picking or fiddling is a mark of the top bluegrass bands just like tight harmonies and accompaniment. Ever since the 1970s or so, bluegrass bands have often incorporated subtle jazz influences with just a dash of creative notes tossed in for flavor while still maintaining the overarching structure that defines the bluegrass style. Here's one example from 2019:
Metal tends to feature each musician, and especially the guitarist(s) in the band playing a shredderiffic solo with fast, clean virtuoso performance. Ever since the 1970s or so, when metal began, artists have incorporated elements of jazz, classical music, and other influences to break away from the standard rock and roll structure from which it was born. Here's a fairly well-known power metal ballad demonstrating some of these factors:
If you played Guitar Hero III, that might bring back some memories. If you thought it was nigh-impossible on those plastic controllers, just look at how they play the real thing live.
The crowd dynamic and audience interactions are completely different, but both styles are built around an intricate performance where the audience expects to see not just some fun music, but truly phenomenal musicians who are masters of their craft. The only way to be that good is to have a far deeper knowledge and understanding of music theory than I will ever achieve.
What other unlikely comparisons can you find between these genres or others where fans have an unlikely overlap in the Venn diagram of fandom? Comment below!