Music in Japanese animation is often closely tie to the Japanese pop music industry, but is also a significant industry in its own right. It is common for television and original video animation series to be accompanied by soundtrack albums, which may include the opening ("OP"), ending ("ED") and insert songs, incidental music, original songs ("image songs") and drama tracks (short plays featuring the show's voice actors). Established Japanese musical acts often perform songs featured in animation series or movies. Likewise, it is not uncommon for voice actors ("seiyū") from anime shows to have a music career in their own right; Megumi Hayashibara, Rie Tanaka, Mizuki Nana, Sakamoto Maaya, and Mariko Kōda are among numerous seiyū who have also recorded music independent from anime.