<p>in the original Macross universe, you can see that the Zentradis are created by the Protoculture for combat purposes, that's why they left out sense of perception and appreciation towards "culture" (where a song is a product of human culture) which is not needed in combat. So when the powerful Zentradis hear a song for the first time, it causes disruption and arouses their basic instinct of wanting to appreciate something that is considered beautiful, a concept that is unknown to them before. at first it made them uncertain but then they became more interested and wanting to hear more. the songs that Minmay sang in the series brought them together and communicate each other thus ending the war. </p><p><span style="font-weight:normal;">basically it was a message, that a song is a universal language. it can reach every living being, be it human or alien and opens up communication between them. A song is more powerful than any weapons, that it can stop war and make peace between any race across the galaxy.</span> </p><p><span style="font-weight:normal;">That's why characters in Macross sing.</span> </p>