Year 664 (DCLXIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 664 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Armin van Buuren (Dutch pronunciation: [ˈɑr.mɪn vɑn ˈby.rə(n)]), OON (born 25 December 1976 in Leiden, Netherlands) is a Dutch trance producer and DJ. Between 2007 and 2010, he was voted number one in DJ Magazine's annual top 100 list of the most popular DJs. In the 2011 list, he ranked in second place. Since 2001, Van Buuren has hosted a weekly radio show called A State of Trance, which claims to have around 15 million weekly listeners in 26 countries, which would make it one of the most listened-to radio shows in the world. His 2008 studio album, Imagine, entered the Dutch album chart at #1, a first for a dance music artist in Dutch music history.

Armin van Buuren was born in Leiden, Netherlands on 25 December 1976, but grew up in Koudekerk aan den Rijn. Van Buuren started making music when he was 14.^{[citation needed]} He was inspired by French electronic music composer, Jean Michel Jarre, and wished to become a great electronic music composer like Jarre.^{[citation needed]}

He finished high school at the Stedelijk Gymnasium Leiden in 1995, and left for college to study law at Leiden University. While studying law, Van Buuren's interest for making music blossomed, and he began working as a DJ in a local club called Nexus. As his musical career began to take off, he put his law degree on hold, although he did return to finish law school in 2003.

Franz Peter Schubert (German pronunciation: [ˈfʁants ˈʃuːbɛɐ̯t]; 31 January 1797 – 19 November 1828) was an Austrian composer.

Although he died at the age of 31, Schubert was a prolific composer, having written some 600 Lieder, nine symphonies (including the famous "Unfinished Symphony"), liturgical music, operas, some incidental music, and a large body of chamber and solo piano music. Appreciation of Schubert's music during his lifetime was limited, but interest in his work increased significantly in the decades following his death. Franz Liszt, Robert Schumann, Johannes Brahms and Felix Mendelssohn, among others, discovered and championed his works in the 19th century. Today, Schubert is seen as one of the leading exponents of the early Romantic era in music and he remains one of the most frequently performed composers.

Schubert was born in Himmelpfortgrund (now a part of Alsergrund), Vienna, on 31 January 1797. His father, Franz Theodor Schubert, the son of a Moravian peasant, was a parish schoolmaster; his mother, Elisabeth Vietz, was the daughter of a Silesian master locksmith, and had also been a housemaid for a Viennese family prior to her marriage. Of Franz Theodor's fourteen children (one illegitimate child was born in 1783), nine died in infancy; five survived. Their father was a well-known teacher, and his school in Lichtental, a part of Vienna's 9th district, was well attended. He was not a musician of fame or with formal training, but he taught his son some elements of music.

András Schiff (Hungarian pronunciation: [ˌɒndraːʃ ˈʃifː]) (born 21 December 1953) is a Hungarian-born British classical pianist and conductor, who made numerous recordings and is one of the most highly honored pianists of our time, having won numerous major awards. He has also become an outspoken critic of the Hungarian government of Viktor Orbán, whom he has publicly accused of racism, anti-Semitism, and neo-fascism, stating in January 2012 that he would never again set foot in his native country.

Schiff was born in Budapest into a Jewish family and began piano lessons at the age five with Elisabeth Vadasz. He studied at the Franz Liszt Academy of Music in Budapest until 1974 and in London with George Malcolm. He was a finalist in the Leeds International Pianoforte Competition in 1975. He emigrated from Hungary in 1979. He was unable to meet requirements for US citizenship because of his long absences for touring , and accepted Austrian citizenship in 1987 and established homes in London and Salzburg. He became a British citizen in 2001. He is married to the violinist Yuuko Shiokawa, and resides in London, England, and Florence, Italy.

Sviatoslav Teofilovich Richter (Russian: Святослав Теофилович Рихтер Sviatosláv Teofílovich Ríkhter, Russian pronunciation: [svʲjətəsˈlaf tʲɪəˈfʲiləvʲɪtɕ ˈrʲixtər], Ukrainian: Святослав Теофілович Ріхтер; March 20 [O.S. March 7] 1915 – August 1, 1997) was a Soviet pianist well known for the depth of his interpretations, virtuoso technique, and vast repertoire. He is widely considered one of the greatest pianists of the 20th century.

Richter was born in Zhytomyr, Ukraine. His father, Teofil Danilovich Richter (1872–1941), was a German expatriate pianist, organist, and composer who had studied in Vienna. His mother, Anna Pavlovna (née Moskaleva; 1892–1963), was from a landowning Russian family, and at one point had been a pupil of her future husband. In 1918, when Richter's parents were in Odessa, the Civil War separated them from their son, and Richter moved in with his aunt Tamara. He lived with her from 1918 to 1921, and it was then that his interest in art first manifested itself, although he first became interested in painting, which his aunt taught him.