Being a long-running Light Novel with a popular Spin-Off, both of which have currently two seasons of animated adaptation each, A Certain Magical Index (as well as A Certain Scientific Railgun) brings a great deal of songs to the table, and all of them are awe-inspiring.
- All four openings ("PSI-missing"
, "masterpiece", "No buts!" and "See visionS") have a techno vibe and electronic synth that perfectly captures Academy City as a state of the art future city, as well as capturing the hectic life style that Touma constantly finds himself in. - Index's Theme Music Power-Up, "jellyfish", first plays when Index faces Sherry Cromwell's golem, with the entire song starting off rather slow before throwing more instruments that immediately pick up the speed of the song while also occasionally throwing in brief spurts of lyric here and there that briefly slow the song down a little before picking right back up, all leading to an ebb and flow just like a jellyfish drifting in the water.
- Episode 12 of Index Season 1, where Touma confronts Misaka who is planning to throw her life away to save the Sisters before he convinces her not to, gives us the insert song "Ame", with lyrics about how Touma will always be ready to reach out a hand to any one in need.
- "King of Witch Hunters (Majou Kari no Ou)" is a hauntingly scary song that plays after Aureolus Izzard first cuts off Touma's arm.
- "Overdrive" is the first theme that plays in Index, and its electric and reverse bass clue you in that this is going to take place in a super advanced city with all sorts of robots and powers being thrown around.
- "Turnabout (Gyakuten)" plays when Touma and Accelerator first battle. Its slightly upbeat rhythm shows that Touma has the power to take down the number 1 esper in Academy City, but it also has a rather intense beat that signifies that Accelerator is going to make Touma work for his victory.
- Touma's themes, "Imagine Breaker (Gensou Goroshii)" and "Breakthrough", signify that who ever he's facing is about to have their plans destroyed and a fist to their face.
- The second season has some downright brutal battle theme songs: "Greater Power (Kyoudai no Chikara)", "Scheme (Sakubou)" and "A Shadow Draws Near (Semaru Kage)", which also doubles as Accelerator's new theme song. Who says anime fights and trance music can't go well together?!
- The second OST gives us "New Fight (Arata Naru Tatakai)", "Large-scale Magic (Dai Majutsu)" and "The Queen's Fleet (Joou Kantai)". Also, "Hymn (Seika)" supplies our daily dose of Soundtrack Dissonance when Accelerator awakens and punches Kihara so hard the man burns up in the fucking atmosphere while flying away.
- "Sheol Fear", a mysteriously solemn track which plays when Index performs Sheol Fear spell to exploit the contradictions of the Roman Catholic Church doctrines and use it as a weapon to hurt the religiously fanatical Roman Catholic nuns.
- From the Spin-Off, A Certain Scientific Railgun:
- "Electric Chase" is the perfect theme song of Mikoto's tsundere side, so much so that it was reused in the second season of Index!
- "Frenda" adds more intensity to an already intense and gritty Sister arc and proves to the fans that a Level 0 esper can be badass too.
- The 1st OP, "only my railgun", showcases protagonist Mikoto Misaka's character with a fast tempo matching her quick temper, and electronic beats matching her powers (Shock and Awe).
- The second opening, "LEVEL5-judgelight, kept what was good with the first opening and added a different set of lyrics, showing Mikoto's firm resolve in becoming a hero.
- "Electric Chase"
- A Certain Scientific Accelerator's opening theme, "Shadow is the Light", is the perfect theme music for the Strongest Esper, and ditches the usual synthpop sounds from the other openings for a heavier Industrial Metal sound with lyrics that perfectly encapsulate Accelerator's journey from villain to hero.
- For the A Certain Magical Index TV Songs Album, the singers of the openings and season 2 endings (Mami Kawada and Maon Kurosaki respectively) got together for a duet called "Snap out of it!!". Needless to say, it makes a perfect addition to the series fantastic music catalogue.
