在 F - G - Em - Am 上生成旋律

Opening on IV gives it lift from the first beat, and instead of resolving from V to I it slips through iii to land on vi — a deceptive cadence. Because it never fully resolves, it loops well through a chorus. Em (E, G, B) shares tones with both F and G, so a held melody note across bar three still sits cleanly.