Question: Where did the second single from the September 15, 2017 Foo Fighters album peak on the Billboard" Mainstream Rock Songs chart?

Context paragraphs:
List of Foo Fighters band members: Foo Fighters is an American alternative rock band formed by multi-instrumentalist and vocalist Dave Grohl in 1994.  After recording the album "Foo Fighters" alone, Grohl enlisted guitarist Pat Smear, bassist Nate Mendel and drummer William Goldsmith to join the band.  This lineup recorded the second Foo Fighters album, 1997's "The Colour and the Shape", although most of Goldsmith's drum recordings were removed and re-recorded by Grohl for the release, after he left the band due to creative tensions.  Goldsmith was replaced by Taylor Hawkins, and Franz Stahl replaced Smear after he also departed, although he only remained in the band for a short period and did not record an album with the group.  The group's third album, "There Is Nothing Left to Lose", featured Hawkins on drums and was released in 1999.

Outside (Foo Fighters song): "Outside" is a song by American rock band Foo Fighters released in August 2015.  It is the fifth official single and third radio single from their eighth studio album, "Sonic Highways".  The song marked a 30th appearance by the Foo Fighters on "Billboard"' s Alternative Songs chart tying them with Green Day and Red Hot Chili Peppers for third-most appearances.

Saint Cecilia (EP): Saint Cecilia is an EP by American rock band Foo Fighters.  It was released as a free download on November 23, 2015.  Initially intended as a sign of gratitude to the group's fans, the EP was also dedicated to the victims of the terrorist attacks in Paris.  A single from the EP, "Saint Cecilia", peaked at number 3 on the "Billboard" Mainstream Rock Songs chart in 2016.

Monkey Wrench (song): "Monkey Wrench" is the first single released from the second Foo Fighters album, "The Colour and the Shape".  The lyrics chronicle the 1997 disintegration of singer/songwriter Dave Grohl's four-year marriage to Jennifer Youngblood.  The song peaked at number 9 on the "Billboard" Mainstream Rock Tracks chart, and at number 12 on the UK Singles Chart.

Concrete and Gold: Concrete and Gold is the ninth studio album by American rock band Foo Fighters.  It was released on September 15, 2017.  The album's first single, "Run", was released on June 1, 2017, and topped the US "Billboard" Mainstream Rock Songs chart the following month.  The second single, "The Sky Is a Neighborhood", was released on August 23, 2017.  A third song, "The Line", was released a week prior to the album's release.  The album received positive reviews, and topped the US all-format "Billboard" 200 chart in its debut week of release, selling 120,000 copies.

Songs from the Laundry Room: Songs from the Laundry Room is an EP by American rock band Foo Fighters, released exclusively for Record Store Day 2015.  This EP and the Foo Fighters album are the two Foo Fighters releases upon which Dave Grohl plays all the instruments.

The Sky Is a Neighborhood: "The Sky Is a Neighborhood" is a song by American rock band Foo Fighters.  It was released as the second single from their ninth album "Concrete and Gold" on August 23, 2017.  As of September 2017, the song had peaked at number 7 on the "Billboard" Mainstream Rock Songs chart.

Saint Cecilia (song): "Saint Cecilia" is a single by American rock band Foo Fighters, off of their EP "Saint Cecilia".  It peaked at number 3 on the "Billboard" Mainstream Rock Songs chart in 2016.

Check My Brain: "Check My Brain" is a song by the American rock band Alice in Chains, featured on their fourth studio album "Black Gives Way to Blue" (2009).  It was released as the second single from the album on August 17, 2009.  The single topped the "Billboard" Hot Mainstream Rock Tracks and "Billboard" Rock Songs charts in September 2009.  This was the first time an Alice in Chains song would hit #1 on the Hot Mainstream Rock Tracks chart since their 1994 single "No Excuses".  "Check My Brain" received a nomination for "Best Hard Rock Performance" at the 52nd Grammy Awards.  It was also their first #1 on the Alternative Songs chart.

Run (Foo Fighters song): "Run" is a song by American rock band Foo Fighters.  It was released as a single on June 1, 2017, and is off their ninth studio album, "Concrete and Gold".  The song topped the US "Billboard" Mainstream Rock Songs chart in July 2017.

Supporting paragraphs: Concrete and Gold The Sky Is a Neighborhood
Answer: number 7