His shaky vocals and laconic way with lyrics are uncannily like Tom Petty's. Yet Droge's melodies and observations are all his own. On his fourth solo album, Skywatching, the Seattle-based alt-rocker goes for his most scaled-down and homey sound to date. He still writes the sweet pop tunes that gave him his cult hit -- 1994's ''If You Don't Love Me (I'll Kill Myself).'' But now everything seems closer and, as a result, has more consequence.