Opeth's earlier works often made use of twin-guitar harmonies, but they were abandoned in the band's later work. "I got tired of it, the whole harmony guitar thing", Åkerfeldt said. "It got out of hand in the mid-90s. Every band was doing that thing." Most of the band's songs exceed 10 minutes in length, which Aaron Burgess of "Alternative Press" magazine criticized, stating, "you can't really be a casual Opeth fan. It takes enough as a listener just to get past the band's epic song lengths." Vocally, Åkerfeldt shifts between growling death metal vocals for heavy sections, and clean, sometimes whispered vocals over acoustic passages. While death growls were dominant on the early albums, later releases used more clean vocals, such the 2003 release "Damnation" which had only clean singing. The band's lyrics often reflect a bleak outlook on life, with subjects such as failed relationships, nature, death, and depression. Some of the band's albums also have a consistent theme or concept throughout, such as "Still Life" and "My Arms, Your Hearse". The songs were put together as one continual piece, with the last word or phrase of each song becoming the title of the next.