Question: What was the most popular song from the second Van Halen album to feature vocalist Sammy Hagar?
Context: Chickenfoot is a rock supergroup formed in 2008.  The group consists of vocalist Sammy Hagar (ex–Van Halen and Montrose), bassist Michael Anthony (also ex–Van Halen), guitarist Joe Satriani, and drummer Chad Smith (Red Hot Chili Peppers).  Due to consistent recording and touring commitments to the Red Hot Chili Peppers, Kenny Aronoff joined the group in 2011 as a touring replacement for Smith.  While the band has not formally announced a breakup, in June 2016 Smith said that he had doubts about the band touring or recording again due to the busy schedule of each band member. Ray Danniels is a Canadian music executive, record producer, and talent manager.  He's the founder of SRO (Standing Room Only) Management group, as well as independent record labels Moon Records and Anthem Records.  He first rose to prominence as the manager of the Canadian band Rush and later served as the manager of Extreme and Van Halen.  His sister-in-law Kelly Carter was married to Alex Van Halen.  He was instrumental in bringing in Gary Cherone, former lead singer of Extreme, to replace Sammy Hagar as lead singer of Van Halen. "Humans Being" is a song recorded and contributed by the rock band Van Halen for the film, "Twister".  The song marks the last recording to feature vocalist Sammy Hagar before his departure from the band in June 1996. The Best of Both Worlds is the second greatest hits album by American hard rock band Van Halen, released on July 20, 2004 on Warner Bros. The compilation features material recorded with lead vocalists David Lee Roth and Sammy Hagar; omitting Gary Cherone's three-year tenure with the band.  Prior to "The Best of Both Worlds"' release, Hagar reunited with Van Halen, and the band subsequently recorded three new tracks to include on the release. "Finish What Ya Started" is a song by Van Halen taken from their 1988 album "OU812".  Despite the album being seemingly complete, Eddie Van Halen came up with the riff at 2 in the morning and went down to his then-neighbor Sammy Hagar to show it.  Hagar let Eddie in, and the two played guitars in his balcony until they had a completed song.  Once Eddie left, Hagar decided to write the lyrics despite being late at night.  The theme wound up being unfulfilled sex, summed up by Hagar as "blue balls.  In the song, Eddie Van Halen recorded his guitar part on a Fender Stratocaster plugged direct into the studio mixing console.  The song is one of only two Van Halen tracks featuring Sammy Hagar playing a rhythm guitar part, which he played on a Gibson acoustic. OU812 (pronounced "Oh You Ate One Too") is the eighth studio album by American hard rock band Van Halen, released in 1988, and the second to feature vocalist Sammy Hagar.  Van Halen started work on the album in September 1987 and completed it in April 1988, just one month before its release. "Why Can't This Be Love" is a song by the American rock band Van Halen for their seventh studio album, "5150" (1986).  The song was released as the lead single from "5150" on February 26, 1986 through Warner Bros.  Records.  It was the group's first single with lead vocalist Sammy Hagar, who replaced founding member David Lee Roth.  It was released on both 7" and 12" single formats, the 12" single featuring an extended version of the song.  The song is driven by bouncy lead keyboard work from Eddie Van Halen performed on an Oberheim OB-8. "When It's Love" is a power ballad by the American rock band Van Halen.  It was released as a single from their album "OU812".  It was the most popular song from that album, hitting #1 on the "Billboard" Mainstream Rock charts and #5 on the "Billboard" Hot 100 chart.  The song has been a live performance staple since it was released in 1988.  The song was also included in the set list for the band's ill-fated 1998 tour with Gary Cherone.  Eddie has stated that this particular guitar solo is a nod to Eric Clapton. "Right Now" is a rock song written by the group Van Halen for their album "For Unlawful Carnal Knowledge".  The song reflects on living for the moment and not being afraid of making a change.  Vocalist Sammy Hagar has said that he was writing the lyrics to this song at the studio very late one night, and he heard Eddie Van Halen in an adjacent room working on a piano melody.  Hagar said he suddenly realized that "we were writing the same song," so he walked into the room and began singing his words over Van Halen's music.  According to Eddie, the instrumental dates back to 1983, "before I wrote "Jump" - it didn't come out until about '92, '93 or something like that, cause nobody wanted anything to do with it."  An early version of the melody appears in the 1984 movie "The Wild Life" which was scored by Eddie Van Halen.  Eddie also stated that before Hagar was hired to replace David Lee Roth, he considered an album that would feature various guest singers, with Joe Cocker assigned to "Right Now". The Balance Tour was a concert tour by hard rock Van Halen promoting their album Balance.  It was dubbed the "Ambulance" Tour by Eddie Van Halen due to his hip injury caused by avascular necrosis, and his brother, drummer Alex Van Halen wearing a neck brace for most of the tour, due to rupturing three vertebrae in his neck.  Consequently, Eddie was a lot more static on stage.  This would be the group's last tour with Sammy Hagar on vocals until 2004, when he briefly rejoined the band for a summer tour.  The opening night in Pensacola, and a combination of footage from the two Toronto shows were broadcast on Pay-Per-View.
Answer: When It's Love