The Magic Door is the second studio album by American blues rock band Chris Robinson Brotherhood.
 It was released on 11 September 2012.
 It was recorded at the same time as their previous album, "Big Moon Ritual", and features a cover of Hank Ballard's "Let's Go, Let's Go, Let's Go", which the band has frequently performed live.
 "Appaloosa" and "Little Lizzie Mae" are versions of recent Black Crowes songs (from "Before the Frost...Until the Freeze" and "Cabin Fever", respectively), and "Someday Past the Sunset" was previously released on the Robinson brothers' live album, "".
Truth & Salvage Co. is a six-piece roots rock/Americana band from Los Angeles, California, and currently headquartered in Nashville, Tennessee.
 The band formed in late 2005 when members from Scrappy Hamilton and Old Pike, two simultaneously performing Los Angeles acts, merged and began performing under their current moniker.
 The band gained national attention in 2009, when Black Crowes frontman Chris Robinson signed the group to his Silver Arrow label and gave them the opening slot on his band's tour that year.
 The band released their debut album (produced by Robinson) on May 25, 2010 and their second record, "Pick Me Up", on Megaforce/Sony RED on July 23, 2013.
Pete Loeffler (born October 19, 1976) is a musician, known for his work with the Chicago-area rock band Chevelle, for which he is the lead vocalist and sole guitar player.
"Tightrope" is a song by American rock band Walk the Moon.
 It was written by Chris Robinson, Eli Maiman, Kevin Ray, Nicholas Petricca and Sean Waugaman.
 The song appeared on the band's first major-label debut album, "Walk the Moon", and was later included on its own self-titled EP as the lead track.
Chevelle is an American alternative metal band that formed in 1995 in the Chicago suburb of Wildwood, Illinois.
 The band was originally composed of brothers: Pete Loeffler (lead vocals and guitar), Sam Loeffler (drums and percussion) and Joe Loeffler (bass and backing vocals).
 When Joe left the band in 2005, Geno Lenardo subbed-in as the bassist until he was replaced by Pete and Sam's brother-in-law, Dean Bernardini.
Richard Spencer "Rich" Robinson (born May 24, 1969) is an American musician and founding member of the rock and roll band The Black Crowes.
 Along with older brother Chris Robinson, Rich formed the band in 1984 (originally called "Mr. Crowes Garden") while the two were attending Walton High School in Marietta, Georgia.
 At age 15, Rich wrote the music to what would become one of the band’s first singles; "She Talks to Angels".
T.I. has released several music videos, working with various directors.
 He has also been featured in several music videos for other prominent recording artists.
 T.I.'s first solo music video was for his debut single "I'm Serious", released in 2001 and directed by American music video director Chris Robinson.
 T.I's first lead role was in his first featured film, "ATL", which was also directed by Chris Robinson.
Christopher Mark "Chris" Robinson (born December 20, 1966) is an American musician.
 He was the singer of the rock and roll band The Black Crowes and brother of its guitarist Rich Robinson.
Buffalo Killers are an American rock band comprising guitarist and vocalist Andrew Gabbard, bass guitarist and vocalist Zachary Gabbard and drummer Joseph Sebaali.
 The band was formed in Cincinnati, Ohio, in 2006 following the dissolution of Thee Shams, of which the trio were members.
 Buffalo Killers were quickly signed by Alive Records and their self-titled debut album was released in October 2006; "Buffalo Killers" drew the attention of Chris Robinson, who invited the band to open a string of dates for The Black Crowes in 2007.
 Buffalo Killers' second album, "Let It Ride", was produced by Dan Auerbach of The Black Keys and released in July 2008.
Chris Robinson Brotherhood is an American blues rock band formed in 2011 by Black Crowes singer Chris Robinson while The Black Crowes were on hiatus.
 The band has released four studio albums: "Big Moon Ritual", "The Magic Door", "Phosphorescent Harvest", and "Any Way You Love, We Know How You Feel".
 The band consists of Robinson, guitarist Neal Casal, keyboardist Adam MacDougall, bassist Jeff Hill (who replaced original bassist Mark Dutton in 2016), and drummer Tony Leone (who replaced original drummer George Sluppick in January 2015).

Question: Are Pete Loeffler and Chris Robinson both singers in American rock bands?
Answer: yes