The sound of rezophonic or resonated guitar-DOBRO is characteristic for country music, Hawaiian music, blues, and old-time jazz music. It was regarded as an American folk instrument, even though its inventor John Dopyera (1893-1988) was a native Slovak. He was born in Strafe and lived his childhood in Dolná Krupa near Trnava, from where he and his family emigrated to California in 1908. Dopyera and his brothers opened a music shop in Los Angeles, repairing and producing musical instruments. He made the first application for an American patent for the construction of his special rezophonic guitar in 1926, which he later on improved and named DOBRO according to the title of the company DOpyera BROthers Co. and also to the Slovak meaning. From that time, the rezophonic dobro has spread all over the world, it significantly enriched the sound of popular music and entered history. Dobro became a symbol of the acoustic, the so-called "unplugged" music thanks to its unique sound. In commemoration of John Dopyera and his rezophonic dobro an International Musical Festival Dobrofest in Trnava is dedicated, where the best world's dobro-players meet each year last week of August since 1992.