Yattemita (やってみた, which means "tried to do"), is a section in Nico Nico Douga where people upload videos of them "trying to do things". There are currently five subcategories in this section: utattemita (tried to sing), odottemita (tried to dance), egaitemita (tried to draw), ensoushitemita (tried to do a musical performance), and nico nico gijutsu-bu (arts and technology department).
Utattemita is different from Awasetemita (合わせてみた). The latter means a mashup of two or more renditions of a song. Therefore it is not an original upload of the singer. Rather, a person, often unrelated, though there are exceptions, took a few singers' covers and combined them to make a chorus-like version. Unlike with YouTube Choruses, the Utaite in them are generally not involved.