Complex sentence: Violinist Andreas Ljones contributed addititional music to Rein's version, which was finally picked to become one out of a total of 464 songs to apply for the Melodi Grand Prix 2007 and moreover made the final selection of the 18 participating entries.
Split into simpler sentences: Violinist Andreas Ljones contributed addititional music to Rein's version, which was picked to apply for the Melodi Grand Prix 2007. Chosen out of a total of 464 songs, it eventually made the final selection of the 18 participating entries.