Background: Bloc Party are an English rock band, currently composed of Kele Okereke (lead vocals, rhythm guitar, keyboards, sampler), Russell Lissack (lead guitar, keyboards), Justin Harris (bass guitar, keyboards, saxophones, backing vocals) and Louise Bartle (drums, percussion). Former members Matt Tong and Gordon Moakes left the band in 2013 and 2015 respectively. Their brand of music, whilst rooted in rock, retains elements of other genres such as electronica and house music. The band was formed at the 1999 Reading Festival by Okereke and Lissack.
Context: Bloc Party's debut album, Silent Alarm, was released in February 2005 and was met with universal critical acclaim. It was voted 'Album of the Year' for 2005 by NME, and reached number 3 on the UK Albums Chart before being certified platinum. The first single from the album, "So Here We Are/Positive Tension", made the top 5 on the UK Top 40 chart. Further singles "Banquet" (which reached number 13 in NME's 'Top 50 Singles of 2005'), "Helicopter", and "Pioneers", whilst failing to repeat this success, still managed to reach the UK top 20. The animated video for "Pioneers," made by the Shoreditch-based Minivegas design agency, was top of the NME video charts for four weeks. NME tagged them as "art-rock" at that time but the band felt it was too limited.  The band received positive reviews from critics in the United States and they toured there heavily in the 18 months that followed the release of Silent Alarm. In early 2006, they finished their tour with sold out shows in Los Angeles, Miami and Berkeley. The album went on to sell more than 350,000 copies in North America and over a million worldwide. After this success, the established electronic group, The Chemical Brothers, soon collaborated with Okereke for "Believe", a track on their Push the Button album. An album of remixes of tracks from Silent Alarm had also been released at the end of August 2005 in the UK. This remix album, entitled Silent Alarm Remixed, retained the album's original track list and includes remixes from the likes of Ladytron, M83, Death from Above 1979, Four Tet, and Mogwai.  During July 2005, Bloc Party recorded two new tracks with Silent Alarm producer Paul Epworth. The songs were released as a single with a B-side, titled "Two More Years", to coincide with the band's October 2005 UK tour. The tour was also accompanied by a re-issue of Silent Alarm, which included "Two More Years" and former single "Little Thoughts" as bonus tracks. A remix of "Banquet" by The Streets, as well as a music video for the song, were included in the "Two More Years" single. Bloc Party also contributed the track "The Present" to the Help!: A Day in the Life compilation, the profits of which benefited the War Child charity.
Question: What is silent alarm?

Answer:
Bloc Party's debut album,