After Day 1, between 11 AM and 7 PM, the Yusnaan side-quest Songless Diva becomes available and should be addressed as soon as possible, in order to increase the time Lightning has until the end of the world.
Lightning Returns: Final Fantasy XIII Songless Diva side-quest can be compared with Play It For Me, because it doesn’t require any main-quests in Yusnaan.
Additionally, it should be activated and finished as soon as you finish Play It For Me, since the client, Olga, is located close to Morris.
Description: “In the Fountain Square, Reveler’s Quarter, Lightning meets a singer called Olga who has been abandoned by Berdy, her lover and songwriting partner. If Lightning were to find the wayward Berdy, it could help the diva get her voice back.”
Requirements: Start at 11 AM, end it before 7 PM, after Day 1.
Rewards: 1400 Gil, Maximum HP + 80, Strength +6, Magic + 6, Queen’s Mask
To begin the quest, first you have to find Olga. From the Cactuar Statue which is located south from the Yusnaan Train Station, head east, and then south towards Fountain Square.
On the street look for a piano, and near it you will see Olga, wearing a blue dress, a mask and a white feather on her head.
Talk to her and she will tell you the story of her life as a singer, offering additional details on her ex-boyfriend Berdy.
Note: During the cutscene that unfolds after you accept the quest, you should pay close attention and spot a man who tries to run. He is located near the same piano, wearing a violet jacket, a black mask and a yellow feather on his arm.
The NPC is Berdy and your next objective is to catch him. So the moment the cutscene ends, start running after him and press A (Xbox 360) or X (PlayStation 3) to talk to him.
After the next cutscene, Berdy will tell you that he lost the song he wrote for Olga, and that you must find it; otherwise, he won’t be able to talk to her. In other words, to complete the quest you have to find the missing song; or, as the item is named in the video game, the Music Satchel.
The Music Satchel can be found within the sandy area north from the Warehouse District, but what makes this item hard to find is the fact that it is carried by a group of Gremlins. To find the Music Satchel, cross the Central Avenue and the passage north-east.
Continue to move east as you exit the tunnel and you will reach the beach north from the Warehouse District and south from Industrial Area. When you get to the easternmost point of the beach a large number of Gremlins will spawn.
Attack them and cast Overclock and Thundara for increased AoE damage. Once you defeat them, get the Music Satchel the Gremlins drop, and take it back to Berdy.
While Berdy is happy to return to his beloved, Olga has other plans for him. After the final cutscene you will receive all rewards mentioned above for completing Songless Diva.