 Hartmann also sang in Italian band Empty Tremor, which was a support act for Dream Theater during a 2004 tour in Italy.With his band, Hartmann also supported Toto during their European tour 2006, House of Lords and The Hooters in 2007.During the past two years, the band Hartmann played numerous festivals and shows as support of bands such as Mother's Finest, Uriah Heep and Y&T.