As the others have said, I'm very sorry to hear that.
I'm sure many of the fans here would want specific songs played at their funeral because they loved the song, rather than because of the message or mood it gives. Do you happen to know any of his favourites? Whilst the guests may not appreciate up-tempo songs or mood, if it was your husbands favourite song I would see it to be just as nice a gesture. I guess it depends on what you are aiming for.
Hallowed by thy Name, as Perun says - is one of the bands major tunes. The opening is about a condemned man in a cell, the latter half is more about his coming to terms with whats about to happen, and his views on what comes next. (
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Blood Brothers - If I recall is written about one of the band members fathers who had recently died. It's not a mellow song, but I wouldn't call it uptempo either, and its quite nice. (
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Remember Tomorrow - Flicks back and forth between calm and heavy, my only concern myself would be the lyric "I shall return from out of the fire" - again, this is entirely dependant on whether you are looking for a message. (
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Personally I think the most 'funeral appropriate' song excluding your husbands personal favourites, would be
Journeyman - It's mostly acoustic. (
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I hope this is of some use for you, in what is undoubtedly a difficult decision.