Complex sentence: They have also collaborated with musicians from the US, such as Mr. Rob Hajacos from Nashville, who plays fiddle on most Garth Brooks albums, also plays the fiddle on three of The Hellbillies albums.
Split into simpler sentences: They have also collaborated with musicians from the US. For example, Rob Hajacos from Nashville, who plays fiddle on most Garth Brooks albums, plays on three of The Hellbillies albums.