Reaction in G was a song written by Pink Floyd in 1965 which was always used to open their earlier concerts. Though, many fan recordings exist, They are all very low quality and distorted. However, The song, in full was recorded for the radio BBC show "Top Gear". It is the only known soundboard recording of the song. Only a small 35 second portion of it was used as a bumper for news broadcasts, and can be heard here (The video has nothing to do with the recording). The full song was recorded for the BBC, But was never released.