Out of the Blue" is a 1999 trance single by Dutch DJ Ferry Corsten, under the alias of System F.
It received an original release in the Netherlands under Corsten's own record label, Tsunami, and a full release in the UK with Essential Recordings.
It reached number 14 on the UK Singles Chart and entered the Top 40 in the Netherlands.
It is often regarded as a seminal release in trance music, and helped shape the genre over the following years.