Singing Group Council: An organization that oversees the a cappella rush process and Tap Night, when a cappella groups formally select new members.

The Alley Cats: An all-male group that formed in 1943 when four Yalies sang from atop the Saybrook Tower, the Alley Cats sing a diverse mix including jazz and folks songs.

The Baker’s Dozen: The idea for the BDs arose at a summer party in 1947. Often comprised of athletes, the all-male BD sings timeless classics and Yale standards, along with more modern pieces. Naples is the BD restaurant hangout.

The Blue Blue: A new singing group dedicated to comedy. The Blue Blue is not a member of the Singing Group Council.

Bluedogs: Yale’s newest singing group, the all-male Bluedogs formed in 2000 free from the restrictions of tradition.

Duke’s Men of Yale: The second-youngest all-male a cappella group at Yale, “da doox” formed in 1952. The group’s repertoire includes pop and showtunes, mostly student arranged.

Living Water: Yale’s Christian singing group, the coed Living Water has been dedicated to Christian music since 1979.

Magevet: A coed ensemble devoted to traditional Jewish and modern Israeli songs, Magevet formed in 1992. Magevet, which means towel in Hebrew, is not a Singing Group Council member.

Mixed Company: A coed a cappella group that began in 1981, Mixed Company mixes comedy with singing.

The New Blue: Yale’s first all-female singing group, New Blue formed in 1969. Performances mix musical showmanship with humor.

Out of the Blue: A coed singing ensemble founded in 1988, OOTB specializes in modern pop music. OOTB renditions are characterized by vocal percussion and innovative choreography.

Proof of the Pudding: Yale’s second-oldest all-female a cappella ensemble, Proof of the Pudding started in 1975. Concerts are dominated by classic jazz and swing tunes.

Red Hot & Blue: Yale’s original coed singing group, Red Hot & Blue formed in 1977. The group frequently tours internationally, bringing along its high musical standards.

Yale Russian Chorus: A tenor-bass a cappella group, the Yale Russian Chorus specializes in Slavic choral music. Since its 1953 origin, the group has performed tunes dating from the 12th century to modern times.

Shades: Shades formed in 1988 to represent gospel, R&B, jazz and traditional music. The 18-member coed group prides itself on an ethnically diverse membership.

Yale Slavic Chorus: Founded in 1969, the all-female Yale Slavic Chorus is an a cappella chorus that includes both Yale students and members of the community. Performances focus on Eastern European folk songs. The group is not a member of the Singing Group Council.

Spizzwinks(?): In 1913, four students dissatisfied with the Whiffenpoofs performed at Mory’s, starting Yale’s second all-male a cappella group. That year’s editor of the Yale Banner was uncertain about the new singing group’s name, and added the question mark suffix, which since has become permanent. The Spizzwinks(?) mix their classic performances with humor.

Society of Orpheus and Bacchus: The SOBs began on a Tuesday in 1938 at Mory’s, and the group continues to perform weekly at the York Street restaurant. Members arrange the songs, which range from barbershop quartets to spirituals to traditional Yale songs. SOBs are known for their relaxed attitude to singing.

Something Extra: Formed in 1977, the all-female organization sings a wide range of music, such as pieces from Madonna and Lauryn Hill. Group members arrange all pieces.

Tangled Up in Blue: Tangled Up In Blue is Yale’s folk music group, and is not a Singing Group Council member.

Whim ‘n Rhythm: An all-female and exclusively senior group, Whim ‘n Rhythm is the female counterpart to the Whiffenpoofs. Formed in 1981, the 14 members of Whim sing a wide range of tunes.

The Whiffenpoofs: The world’s oldest and most famous a cappella troupe, the Whiffenpoofs are 14 senior males. Initially after it formed in 1909, the group performed weekly at Mory’s, and the tradition continues even today. The Whiffenpoofs have evolved into a group respected for their renditions of classic tunes as well as more modern pieces.

Yale Glee Club: Yale University’s official chorus, the Yale Glee Club formed in 1861. Today, 90 students make up the coed ensemble.

Yale Freshman Chorus: Affiliated with the Yale Glee Club, the Yale Freshman Chorus has its own director, officers and repertoire, although the style closely resembles that of the Glee Club.