|Modern recorders vary widely in their designs and uses. Some, such as the Moeck Ehlert modern alto and tenor, are designed for the volume and extended range that is often required for demanding 20th century literature. Others, such as the Paetzold square basses, are designed as a new and modern approach at overcoming the difficulties and limitations of original instruments. Still others are designed to be better all-around instruments for all uses than either strictly Renaissance or Baroque instruments. A modern recorder is simply any recorder that does not fit neatly into the category of an historical style.