Sphere Theater
Optional Side Quest Area

The Sphere Theater, or the Luca Sphere Theater rather, is not so much as side quest as it is an optional area that you can visit. Completionists may consider it a side quest though as they seek to purchase and obtain all of the Music and Movie Spheres.

Theater Enthusiast

You will receive the Theater Enthusiast Trophy once you have purchased all of the spheres available at the Luca Sphere Theater.

Theater Enthusiast Trophy
Meeting up with the rest of the team in Macalania Woods

The Music Spheres and Movie Spheres can be purchased for 2,000 gil and 5,000 gil each, respectively. They allow you to listen to music found throughout the game and watch videos and cinematic FMVs that occur as you play through the story.

Meeting up with the rest of the team in Macalania Woods
Tidus traveling through the trails of Macalania Woods

Aside from being interesting pieces to collect, and being a requirement of the Theater Enthusiast Trophy, the Music and Movie Spheres serve no other purpose. The full list of Spheres that can be purchased are included below:

M01: Zanarkand M02: Prelude
M03: Tidus’s Theme M04: Run!!
M05: Creep M06: Battle Theme
M07: Enemy Attack M08: Game Over
M09: Out Of The Frying Pan M10: Victory Fanfare
M11: Leap In The Dark M12: Underwater Ruins
M13: The Blitzers M14: Wandering
M15: Besaid M16: Spira Unplugged
M17: Phantoms M18: The Trials
M19: The Summoning M20: Braska’s Daughter
M21: Yuna’s Theme M22: Good Night
M23: Decision On The Dock M24: Movement In Green
M25: A Fleeting Dream M26: Calm Before The Storm
M27: Face Off M28: Grand Maester Mika
M29: Luca M30: The Splendid Performance
M31: Auron’s Theme M32: Blitz Off!
M33: Mi’ihen Highroad M34: Chocobo Jam
M35: The Travel Agency M36: Seymour’s Theme
M37: Moment of Truth M38: Djose Temple
M39: Ridess The Shoopuf? M40: Rikku’s Theme
M41: Oui Are Al Bhed M42: Guadosalam
M43: Thunder Plains M44: Jecht’s Theme
M45: The Burning Sands M46: The Wedding
M47: Assault M48: Tragedy
M49: Believe M50: Servants of the Mountain
M51: Macalania Woods M52: Via Purifico
M53: Bravely Forward M54: The Unsent Laugh
M55: Seymour’s Ambition M56: Illusion
M57: Yuna’s Decision M58: Nostalgia
M59: Peril M60: Launch
M61: Challenge M62: Beyond The Darkness
M63: The Void M64: The Truth Revealed
M65: Pursuit M66: Gloom
M67: Patricide M68: The Temple Players
M69: Hum of the Fayth M70: Lulu’s Theme
M71: Wakka’s Theme

Movie Spheres

01: Zanarkand 02: We Called It “Sin”
03: Sinspawn 04: This Is It!
05: Blitzball! 06: A Summoner Is BOrn
07: Lulu’s Contempt 08: Kimahri’s Challenge
09: Fear On The Sea 10: Sin Arises
11: Sin’s Threat 12: Futile Resistance
13: Failure 14: Kilika Dusk
15: The Dance 16: Luca Harbor
17: Let The Games Begin! 18: The Legend Lives
19: The Dark Aeon 20: No Better Plan
21: Judgment 22: Ex Machina
23: Sin’s Wake 24: Reunion
25: Metropolis 26: Otherworld
27: Sin Sleeps 28: Homecoming
29: Dry Dock 30: Nayto Du Ku!
31: Leaving Home 32: The Glory Of Yevon
33: The Red Carpet 34: False Vows
35: Believe 36: The Spring
37: The Summit 38: The Last Chapter
39: Sinrise 40: Departure
41: The Approach 42: Terra Graviton
43: Gravity Sucks 44: Heaven’s Fall
45: Vena! 46: Machina Redux
47: Sinfall 48: Evenfall
49: Face Off 50: Breaking Through

The cost of purchasing all of these Spheres can be quite heavy. Check out the tips and tricks section on earning gil for additional tips: