I don't know... I just picture Mako being able to sing. So shoot me. I own nothing but the idea.

Bolin had long since given up on hearing Mako sing again. He remembered his brother's voice - high and childish, but confident - crooning a lullaby to him when he was only a toddler, the firebender's voice melding with their mother's in a lovely harmony. When Momma went up, Mako would go down, and vice versa; one would hold a note while the other continued singing, and then rush to finish the line. Their voices matched.

When Bolin was old enough to know the words, he would try to join in with them, but his voice clunked along while theirs flowed smoothly. Bolin couldn't sing.

But Mako could. His voice only got better as he got older. He still wasn't the greatest singer in the world, but he was his brother's favorite. Clear and strong and sure, that's how he would describe Mako's voice. It was comforting to hear, because Mako singing was the sound of home. The young firebender could hardly move without bursting into song, or at least humming.

Mako stopped singing when he was eight. He didn't even speak for a long time after their parents' death, much less sing. Bolin missed it and was convinced that the firebender mugger had done something to his brother's throat. That was the only thing that could possibly keep him quiet for this long.

"Mako can't hold it in," their mother would laugh, tousling his hair. "He's got music in his blood."

Bolin believed his mother to be wrong; it was until he was eight and finally starting to understand just how much stress Mako endured that he woke one night to the sound of his brother crying.

"Hush, little b-baby, don't s-s-say a word, M-momma's gonna buy y-you a chameleon b-bird..." Mako had whisper-sang, his voice choked by tears. And Bolin understood, then. Mako sang to remember Momma. He forced himself to go back to sleep, not wanting to intrude on Mako's privacy.

Bolin would wake up at night many times after that, not always because Mako was singing. But if he was, then Bolin would try not to listen, wondering when Mako would sing for him again.

As it turned out, not until he was twelve. When Mako had informed Lightning Bolt Zolt that he wasn't going to be able to work for him anymore, the man had punched him in the face. Bolin had been hysterical when he saw his brother's matching black eyes and bloody nose, and Mako couldn't calm him down, until finally the fourteen-year-old pinned his brother's arms to his sides, fixed him with a dead-eyed stare, and began to sing.

"You would not believe your eyes, if ten million glowflies, lit up the worlds as I fell asleep..."

Bolin quieted and listened to his brother voice. Nasaly, from the blood still dripping from his nose, but still pretty good. He stopped crying, closed his eyes, and listened.

That was the last time he ever heard Mako sing. Not even at night did he do it any more; when Bolin woke up, his brother was asleep. He listened in vain, and eventually he gave up.

Four years later, in the place between awake and asleep after being kidnapped by the Equalists, he had a dream. He didn't really know if it was a dream, but he imagined it was, because their was no way it could ever have really happened. He dreamed that Mako snuck up to his side of the attic and sang, his voice low and soft and loving.

"Don't fall in love with the traveling girl, she'll leave you broke and brokenhearted..."

The song didn't match the situation at all - in fact, it was so off it was almost funny, but he sang it gently and Bolin fell asleep to it. Neither of them said anything the next morning.

The next time Bolin heard his brother singing, it was to Asami. He and Bolin shared a room at the Air Temple, and when he heard the door open and the crying girl enter, he considered leaving to give them their privacy, then decided that would be rude. He would just pretend to be asleep.

He couldn't hear their words, just their voices, and he smiled slightly when Mako sang to her. Momma was right; the man had music in his blood.

His voice calmed Asami and lulled Bolin to sleep.