If you're looking for manga similar to Aikatsu! 4, you might like these titles.
Mana Nagase is a high school girl from Hoshimi City who loves to sing. One live performance leads her to become a top idol and she starts to shine.
Two childhood friends, Karen Aijō and Hikari Kagura make a promise that one day they will reunite in the "Revue Starlight" stage after they watch a stage perfomance. Several years later, Hikari returns to Japan after studying abroad in England. She later reunites with Karen and participates in the Revue Starlight with other girls.
To-Y (Fujii To-ii) is a member of the punk rock band GASP. Along with other punk bands, which usually just hanged out doing small gigs, they have this enormous hatred and aversion to the main Japanese music industry, which is dominated by pop music and untalented Idol singers. However, To-Y was tempted by Kado (the Nagel ripoff) of Kama Production, a strong will promoter, to expand out beyond GASP since he has the talent, except she also expect to promote him as an Idol singer, which revolts To-Y.
Welcome to Harmonia Music Academy, a top-class, world-renowned institution of higher learning for musically gifted students and future defenders of mankind. Yes, that’s right – heroes called “Scratch” to defend humanity. We meet our three unlikely heroes, Shuon Tempermento, Calma Perdentosi and Energico Apassio as they completely and utterly fail a critical Scratch placement exam without scoring so much as a single point. “The Problematic Trio”, as they have come to be known, will have to pull together to resolve Shoun’s brother’s mysterious disappearance, the threat of impending war and cope with their own personal turmoil, all while their school careers are on the line. What will happen to them from now on?
Maria got disheartened when she was sent to the Percussion Division of her catholic Music School. There she overheard a Girl playing Wadaiko Drums (Japanese Drums). She was instantly captivated. So she decides to try playing them seriously...
Kuon Otogami was a genius pianist whose name is among the greatest in the annals of the music world. He had seven children who also all became genius pianists. All seven except for the one named Lucky that is. This is the miraculous story of a regular kid taking on godly talent!