Kokoro ga Sakebitagatterunda., Carole & Tuesday Recommendations
Both focus on the musical abilities of the two main characters & their connections to one another. Furthermore, using real-world anthems & tracks as part of the story's development.
Performances are also large features for both anime; emotional, gripping & tearjerking in some cases.
It explores how different backgrounds influence music & how it can be projected to overcome insecurity and thus to find harmony in doing so.