I had the image of pianist Elsa in my head for quite a few days, and this was the result. Although this is technically an Elsanna fic, it's not strictly romantic, so you can easily read it in either a sisterly or romantic way. Whatever your level of comfort is.
Anna had been absentmindedly wandering the halls when she heard the foreign melody drifting from the ballroom. She had never had much of an ear for music, but the piano had always arrested her attention. Elsa used to play, and sometimes Anna could hear the pieces, muffled as they were, as she drifted off to sleep. The song that was traveling through the air captivated her. It was a rather slow piece, played delicately and precisely, almost as though the pianist was afraid to let too much emotion flow through the keys. The control with which it was delivered made the ballad seem almost haunting, and Anna followed its sound, silently opening the door to find Elsa at the piano. She was unsurprised, but moved nonetheless. It had been years since she last heard her sister perform, but she still held such a reserved mastery of the ivories that there was no mistaking her style.
The redhead crept forward, doing everything in her power not to interrupt the piece. She simply couldn't keep herself at bay in the doorway.
"Anna, don't lurk," Elsa reprimanded, a teasing hint in her voice. Her eyes remained fixed on the piano, but it was clear that her focus had been successfully captured by her little sister. The song continued on without a fumble.
Taking the chastisement as an invitation, Anna sat on the bench beside her. She watched her sister's pale fingers lightly dust the keys as they yielded the bizarrely poignant tune. Wrapping her arms around Elsa's waist, she asked, "What're you playing?"
Elsa had obviously not expected the question, and a small patch of color rose in her cheeks. "Oh… it's nothing," she dodged like an expert, this time showing that she needed to concentrate a little harder to maintain the detached quality.
The corners of Anna's lips tugged into a slight pout, and she pressed herself closer to her sister, "It doesn't sound like nothing." At the contact, Elsa played the chord a little too loudly. She cleared her throat and kept playing. However, each note was infused with an audible melancholy that she scrambled to suppress.
Anna listened intently, impressed with her sister's sense of artistry, but a little concerned with her tight lips. They hadn't gotten into the habit of keeping secrets and Anna didn't want to be the first one to push. Instead, she watched Elsa's long digits and allowed her glance to flit occasionally to her face. The princess noticed that the blonde wasn't following any sheet music and it appeared that she was drawing the piece from deep in her memory, if only for the infrequent concerned twitch of her eyebrow, as if she was afraid she would make a mistake. Anna decided to draw a conclusion, "When did you write this?"
Looking down at her sister with an amused expression, Elsa relented, "The night you thawed."
That shut Anna up for several moments as she paid closer attention to the song, seeing as the queen had finally given up on holding back. What had started as a guarded and slow ballad had transformed into nothing short of a decadent requiem. The blonde really hadn't needed to emphasize her performance to prove her point, and Anna's heart hurt at every note. The beautifully layered soundscape barely hid the heartbreak. It made it painfully obvious what Elsa had been feeling in the moments after her sister's sacrifice. Anna hadn't really thought about it, truthfully, as she had been much too busy trying to monopolize Elsa's time from there on out. The past was difficult to talk about, to say the least. Hearing Elsa's grief and surrender resonating through the room only made it that much worse.
Feeling more than a little responsible, Anna removed herself from her sister's side and reached up and gently placed her lips on her cheek. She moved close to Elsa's ear to whisper, "Which you don't have to worry about ever again."
Elsa chuckled dryly, "Better control over my powers has nothing to do with the likelihood that you're going to risk your life again." There was a ghost of a smile on her face.
Anna blanched. The song had calmed down, apparently having moved on to their first embrace in years, but she couldn't help mulling over the comment. She couldn't have let Hans kill Elsa, and she reacted entirely on impulse. She hadn't thought of what it would mean to her sister to be the one left behind. Anna huffed, "Yes, it was reckless. I'm sorry, but I love you, and that was the only thing I could think to do."
Without taking her eyes off of the piano, the blonde countered, "I know, Anna. I swear it'll never come to that again."
Anyone who didn't know the queen would have taken her tone as laced with anger. Her little sister, however, recognized the fear and the hint of self-loathing. Thirteen years inside one's own mind can do that to a person. Anna nuzzled into Elsa's collarbone and sighed, overcome with the need to apologize, but almost entirely at a loss for words.
"You don't have to worry about me leaving you. Not after I've waited so long to get you back."
At that, the music stopped entirely. The snow queen wrapped an arm around her sister and ran a hand through her strawberry blonde locks. She returned her right hand to the keys, saying, "I've got something else I think I'd much rather play for you." This time, it was an intricate yet soothing lilt, and it seemed a little too complex to be accomplished with just five fingers, but she managed.
Anna looked up, noticing that Elsa was making no effort to free her left arm, "You're seriously going to play like this?"
This time, Elsa's smile was vibrant. She pulled the younger woman close, kissed her forehead and replied with an arched brow, "Do you really think I'd write you a lullaby that would require both hands?"