Question: Rob Halford and Brad Delp are both what?

Context paragraphs:
Beatlejuice: Beatlejuice is an American Beatles cover band based in New England.  It initially featured Brad Delp, former front-man of the band Boston, on vocals, and has continued with other members since Delp's death in 2007.

Resurrection (Halford album): Resurrection is the debut album by the band Halford released in 2000.  It was recorded over thousands of hours of work from August 1998 to June 2000.  The album marks the return of Rob Halford's heavy metal roots after several years of musical experimentation.  In 2006, "Resurrection" was remastered and released with an expanded, reorganized track list on iTunes, and was later released on CD in 2009.  The album features "The One You Love to Hate," a duet with Iron Maiden vocalist Bruce Dickinson.  "Silent Screams" is a re-recorded song that was originally demoed by Halford's previous band 2wo.

Halford (band): Halford is an American heavy metal band formed in 1999 by British singer Rob Halford, who is best known as the lead vocalist for Judas Priest.  Halford formed the band to return to his heavy metal roots.  His two previous projects were a "street metal"-style band called Fight and the industrial metal band 2wo.

Life, Love &amp; Hope: Life, Love & Hope is the sixth studio album by American rock band Boston.  It was released on December 3, 2013 by Frontiers Records, making it their first studio album in eleven years.  It is the first album released following the death of Brad Delp.  Delp recorded vocals on the songs "Didn't Mean to Fall in Love", "Sail Away", "Someone", and "Te Quiero Mia", the last of which being a re-arrangement of "I Had a Good Time", from "Corporate America".

Rob Halford: Robert John Arthur Halford (born 25 August 1951) is an English singer and songwriter, who is best known as the lead vocalist for the Grammy Award-winning heavy metal band Judas Priest and famed for his powerful wide-ranging voice.  AllMusic says of Halford: "There have been few vocalists in the history of heavy metal whose singing style has been as influential and instantly recognizable", possessing a voice which is "able to effortlessly alternate between a throaty growl and an ear-splitting falsetto".  Halford was voted number 33 in the greatest voices in rock by Planet Rock listeners in 2009.  In addition to his work with Judas Priest, he has been involved with several side projects, including Fight, 2wo and Halford.  In 1998, he came out as gay in an interview with MTV News.

Brad Delp: Bradley Edward Delp (June 12, 1951 – March 9, 2007) was an American singer and songwriter, best known as the lead vocalist of the rock bands Boston and RTZ.

Delp and Goudreau: Delp And Goudreau features Brad Delp and Barry Goudreau with Tim Archibald, Brian Maes, David Stefanelli, Patty Barkus, Lou Spagnola, and Jack o-Soro.  The album was recorded in Goudreau's home studio, featuring new tracks written by Delp and Goudreau.  Archibald, Maes and Stefanelli also served in Delp and Goudreau's post-Boston RTZ and played on their first and second records.

Halford IV: Made of Metal: Halford IV: Made of Metal is the fourth studio album by the heavy metal band Halford, the solo project of the Judas Priest frontman Rob Halford.  It was produced by Roy Z and recorded during 2009 and 2010.  The album was released on September 28, 2010.  Singles from the album include "The Mower" and "Made of Metal", for which an animated video was made.

Mike Chlasciak: "Metal" Mike Chlasciak (born December 24, 1971) is a Polish-American musician.  Best known as the guitarist for Halford, led by Rob Halford.  With well over a million records sold, Chlasciak and Halford have toured the world several times over with the likes of Iron Maiden, Ozzy Osbourne and Mötley Crüe.  Mike has additionally toured with Bay Area thrash metal band Testament, Saturday Night Live's comedian Jim Breuer and recorded / toured with Sebastian Bach.  Chlasciak's touring has taken him to sold-out concerts at NYC’s Madison Square Garden and the Playboy Mansion.

Halford III: Winter Songs: Halford III: Winter Songs is the third studio album by the heavy metal band Halford, the solo project of Judas Priest frontman Rob Halford.

Supporting paragraphs: Rob Halford Brad Delp
Answer: singer and songwriter