Complex sentence: It is believed to have developed from the traditional Welsh, Scottish, English, and Irish music, along with African influences, and brought to the United States by immigrants and slaves and in turn it influenced country music and old-time music.
Split into simpler sentences: It is believed to have developed from the traditional Welsh, Scottish, English, and Irish music, along with African influences, brought to the United States by immigrants and slaves. In turn it influenced country music and old-time music.