Jan Dettwyler (born 19 October 1978), professionally known as Seven, is a swiss R'n'B, soul, and pop singer and musician.

As the son of a pianist and a tenor, music was practically laid in his cradle. However, instead of a career in classical music, the musician and singer decided on a completely different direction, namely soul and R'n'B … with great success.

In his native Switzerland, he has long been a welcome permanent guest in the charts. In Germany, he has been known at least since his participation in the third season of “Sing meinen Song – Das Tauschkonzert”.

In Switzerland, Seven has been a star for many years now. However, he only made his debut in Germany in 2011. Since then, and at the latest since his participation in the Vox exchange concert, he has also become a celebrated artist in this country.