Music may be memorized, or it may be carried on flip folders, which are held by lyres that clip onto the instruments. Having music memorized is usually considered an advantage for competitive bands, and at competitions, there is usually a penalty for the use of the sheet music on the field written into the scoring rubric. Practically, memorization prevents obstruction of vision caused by the folders. The memorization of music is usually a matter of pride for the marching band, however, bands that regularly pull from expansive libraries and perform dozens of new works each season are more likely to utilize flip folders.