Guitarist Bob Kulick, a longtime Kiss sideman, and older brother of former-Kiss guitarist Bruce Kulick, has died at age 70, with a cause of death still not announced, according to Guitar World. Bob Kulick became part of the Kiss inner-circle upon unsuccessfully auditioning for the band in 1972 and losing out to Ace Frehley. Kulick went on to sub for Frehley on the studio tracks from 1977's Alive II -- and the following year handled lead guitar duties on Paul Stanley's self-titled solo debut. Both Kulick brothers went on to serve as Meat Loaf's guitarists during his legendary tour behind his 1977 multi-platinum Bat Out Of Hell album.

Kulick went on to add lead guitar to four new tracks on Kiss' 1982 overseas compilation, Killers. He went on to tour with Paul Stanley in 1989 during the Kiss co-founder's sole tour apart from Kiss. It was at Bob's urging that his younger brother Bruce became the band's guitarist from 1984 to 1995.

Bob Kulick, who was romantically involved with actress Stella Stevens for decades, performed and recorded with Lou Reed, W.A.S.P., Michael Bolton, Diana Ross, Was (Not Was), Motorhead, Mark Farner, and Alice Cooper, among many others. In 2005, Kulick co-wrote the Spongebob Squarepants song "Sweet Victory," and in 2017 released his last solo album, titled Skeletons In The Closet.

Bruce Kulick announced his brother's death on Twitter, saying: "I am heartbroken to have to share the news of the passing of my brother Bob Kulick. His love of music, and his talent as a musician and producer should always be celebrated. Please respect the Kulick Family's privacy during this sad time. RIP."

Kiss posted a tribute to Bob Kulick, stating: "We are heartbroken. Our deepest condolences to the Kulick family in this difficult time."

Ace Frehley wrote: "I was very saddened to hear that one of my fellow rock guitarists, Bob Kulick, passed away at age 70. Bob and I were friends, and we always treated each other with great respect. We were lucky enough to jam together at a few conventions, which was a lot of fun. Bob was an excellent guitarist and studio musician who performed on many more records than I have over the years, which didn't surprise me because of his great talent. He will be greatly missed in the music community, and my heart goes out to his brother, Bruce, who I'm friends with, and the rest of the Kulick family."

Meat Loaf posted on Facebook: "Bob Kulick. One of the band members on the Bat Out Hell tour witch started in Oct of 1977 an ended in Oct of 1978. Bob rocked that stage with his brother Bruce. His contribution to that year can never be repaid. We started with being booed in Chicago but not off that stage, NOT US. We came to Rock and we did for a year. The end of that year Bat had sold almost 7 million in the states. We were headlining to thousands. Bob we could not have done it without you. . . Bob I love you and will miss you - Meat"

During a recent chat with The Social Media Show, Bob Kulick touched upon his connection with Kiss: "Kiss, at the time -- Wicked Lester -- was one of the bands that advertised for a lead guitar player. So, I went down and auditioned for the band. And while I didn't get the gig, I did impress the guys -- Gene and Paul, especially enough -- that I became their friend. And when the time came that they needed some 'hired gun playing,' shall we say, where they needed a ghost guitar player to come in and play, they called upon me. So, on Kiss Alive II, some of the solos and some of the other guitar parts were me. And I went on to play on Paul's record and write some songs with Gene."

AUDIO: BOB KULICK ON HIS KISS CONNECTION