Complex sentence: For nearly a year, Jeff Scott Soto from Talisman filled in, with the band for several months referring to him as their official lead singer, but in June 2007, the band announced that Soto was no longer with them.
Split into simpler sentences: For nearly a year, Jeff Scott Soto from Talisman filled in, with the band for several months referring to him as their official lead singer. But in June 2007, the band announced that Soto was no longer with them.