Question: Have singers Jessicka and Chuck Billy appeared in the same band?

Context articles: Billy's Boots
Chico Bento – Pavor Espaciar
Jessicka
Thrash of the Titans
Chuck Billy (Chuck Billy 'n' Folks)
Testament (band)
Steve Souza
Billy Keikeya
Chuck Billy (vocalist)
Demonic (album)

Billy's Boots was a popular British comic strip by writer Fred Baker and artist John Gillatt, later continued by Mike Western.
 The original Billy's Boots was an earlier humorous series, written and drawn by Frank Purcell, which appeared in Tiger between 1961 and 1963, with a similar premise to this later series.
 The later more serious Billy appeared in the first issue of "Scorcher" in 1970, and later moved to "Tiger" when the two comics merged in 1974.
 In 1985 "Tiger" in turn merged with "Eagle" and the strip moved again, however just a year later Billy's adventures relocated once more, this time to "Roy of the Rovers".
 New adventures were included in the weekly comic until May 1990 (later followed by reprints), before he switched to "Best of Roy of the Rovers Monthly".
 The strip also appeared in annuals, including annuals for comics which had themselves ceased publication, and is still fondly remembered by fans of the "golden age" of British boys' comics.
 In Finland and Sweden, "Billy's Boots" was published in "Buster" magazine.
 In the UK, stories based on Billy's earliest adventures appeared in "Total Football" magazine until it closed in 2001, and Billy's story was also reprinted for a few months in the defunct Striker comic.
Chico Bento – Pavor Espaciar ("Chuck Billy - Space Dread") is a 2013 Brazilian graphic novel written and illustrated by Gustavo Duarte based on the Chuck Billy 'n' Folks characters created by Maurício de Sousa.
 It is part of the Graphic MSP series of graphic novels based on Maurício de Sousa characters.
Jessicka Addams (born Jessica Fodera) is an American singer and artist.
 Best known by her stage name Jessicka, she was the front woman of Florida-based band Jack Off Jill and current front for the Los Angeles-based band Scarling.
Thrash of the Titans was a benefit concert held on August 11, 2001 at the Maritime Hall in San Francisco, CA.
 The concert was a co-benefit for Testament vocalist Chuck Billy, who was diagnosed with germ cell seminoma (a rare form of cancer); and Chuck Schuldiner, leader of the death metal band Death, who was also battling cancer.
 The Master of Ceremonies for the evening was S.O.D. vocalist Billy Milano.
 The concert was organized by Walter Morgan.
 The show was announced in May 2001, and all 2300 tickets quickly sold out.
Chuck Billy (Chico Bento in the original Brazilian strips) is the main character from Chuck Billy 'n' Folks, created by Brazilian cartoonist Mauricio de Sousa.
 He is the biggest work of Mauricio after Monica's Gang, and he has his own cartoon magazine and even some VHS and DVD movies, following Monica's steps.
Testament is an American thrash metal band from Berkeley, California.
 Formed in 1983 under the name Legacy, the band's current lineup comprises guitarists Eric Peterson and Alex Skolnick, lead vocalist Chuck Billy, drummer Gene Hoglan, and bassist Steve Di Giorgio.
 In the 34 years since its inception, Testament has had numerous lineup changes, and Peterson has been the only constant member.
 Billy replaced former singer Steve Souza (who left the band to join Exodus as the replacement of Paul Baloff) in 1986, prior to the recording of their first studio album, "The Legacy", and has been a member of the band since.
 Peterson and Billy are the only band members to appear on every album.
Steve "Zetro" Souza (born March 24, 1964) is an American vocalist, best known for his work with the thrash metal band Exodus from 1986 to 1994, and again from 2002 to 2004.
 He rejoined Exodus for a third time in 2014.
 Souza is one of two singers, along with Chuck Billy, for the band Dublin Death Patrol.
 He also sings for the death/thrash metal band Tenet.
 Souza recently announced his new thrash metal project, Hatriot.
 He was also the lead singer for the thrash metal band Legacy (later known as Testament).
Billy Keikeya is a fictional character in the miniseries and television remake of "Battlestar Galactica".
 He is portrayed by Paul Campbell.
 Billy appeared until late in the second season, at which point he was killed by terrorists.
 Paul Campbell has said that his character was killed because he had been unwilling to commit to a five-year contract.
Charles "Chuck" Billy (born June 23, 1962) is an American vocalist, who is best known as the lead vocalist for the thrash metal band Testament.
Demonic is the seventh studio album by American thrash metal band Testament.
 Released in 1997 with original members Chuck Billy (Vocals) and Eric Peterson (Guitar), the record also features artists Derrick Ramirez (Bass), Gene Hoglan (Drums) and Glen Alvelais (Guitar).
 Ramirez was previously the band's first guitarist (although here he is performing on bass guitar), and Alvelais had previously performed with Testament on the 1993 live album, "Return to the Apocalyptic City".