Is a minor sin forgiven if a servant does not repent from it, even if he knows it is a sin and frequently seeks forgiveness?

Minor sins are expiated by avoiding major sins, performing obligatory duties, and frequent seeking of forgiveness. However, listening to musical instruments may be considered a major sin, and persistence in committing a minor sin elevates it to a major one, which is then not forgiven except through a specific repentance. A sin may seem minor in the eyes of a servant, yet be grave in the sight of Allah. Underestimating minor sins leads to major ones, and nothing saves one from this except sincere repentance and abandoning all sins.