[4] Such names, normally intended for comedic effect, have come to define in some part the irreverent attitude found in modern collegiate a cappella.

This growth was fueled in part by stylistic changes that had widespread appeal, and in part by the founding in 1991 of the Contemporary A Cappella Society (CASA) by Deke Sharon and Rex Solomon, which enabled interaction and collaboration of a cappella groups across the United States for the first time.

[9] One of CASA's core values in its promotion of the a cappella community is that of innovation, stating "We develop new methods for singers, groups, fans, and educators to sing, learn, connect, and interact with one another.

"[10] The new style used voices to emulate modern rock instruments, marking a shift away from the more traditional sounds of jazz or classical ensembles and glee clubs to contemporary a cappella, with groups focusing on modern pop music, complete with complex textures and a driving beat (see vocal percussion).

Today, even some glee clubs have a largely pop-music repertoire supplemented only in small part by the traditional genres.

[citation needed] An "arch sing" is a casual, public performance, often held in an archway for reasons of acoustics and shelter from the weather.

In recent years, with the advent of more advanced audio equipment and the ability of a cappella groups to attract income with live performances for pay, there has been increased exploration into the importance of microphones.

Individual microphone use for each member of an ensemble has risen in popularity, allowing for, as Mike Chin of the A Cappella Blog states, a "big,...clear,...crisp" sound in an otherwise acoustically dull performance space.

The integration of these technological advancements continues to shape the sound of modern a cappella music at the college level and beyond.

The groups often benefit from the talent of non-music majors who have significant experience with music, choral singing, or both.

This large roster size is often driven by necessity, as college groups tend to see high turnover due to graduation and changing student commitments.

The South-Asian a cappella circuit, run by ASA, also conducts various regional competitions leading up to All-American Awaaz,[13] their national championship.