left the band and started to focus more on other new projects. Since then, his voice has been heard on well known produc-tions such as AVANTASIA, EDGUY, HAMMERFALL, EMPTY TREMOR and many others. 2005 the first solo album „Out in the cold“ was released and reviewed as „album of the month“ in mags all over the world and being elected as "Song of the year" and "Ballad of the year" with the songs "What if I" and "Into the light". After touring over Europe 2006 as support for rock legend TOTO the second album "Home" was released in early 2007, followed by a tour with HOUSE OF LORDS and HOOTERS where HARTMANN performed acoustic versions of their material for the first time. Supported by three female background singers two exclusive unplugged shows have been filmed/recorded in 2007 for the live DVD „Handmade“. After Oliver had been on world wide tour in 2008 as guitarist/singer for AVANTASIA, a few studio projects and live shows with HARTMANN, the latest studio album „3“ was released in Nov 2009, followed by live shows as special guest of bands as Y&T, MOTHER‘S FINEST and URIAH HEEP. After a 2nd world tour with AVANTASIA in Dec 2010 the live DVD „The flying opera - Around the world in 20 days“ was released in early 2011 and climbed up many European charts to No 1!
After Oliver‘s tour with „ROCK MEETS CLASSIC“ in Jan 2012, the production of the new HARTMANN album „Balance“ is finished and will now be released on the German record label AVENUE OF ALLIES in late May.