Complex sentence: She has written over 100 songs in a mix of genres, including country, gospel, pop, folk, and novelty songs, about 50 of which have been published, and a dozen have been recorded on independent labels.
Split into simpler sentences: She has written over 100 songs in various genres, including country, gospel, pop, folk, and novelty songs. At least 50 have been published, and a dozen have been recorded on independent labels.