The later works are agreed to be difficult and challenging pieces of philosophy.

They are some of the most challenging pieces in the standard piano repertoire.

These are usually the most challenging or visually impressive pieces in the drumline's repertoire.

Often, pianists find it easier to remember a very fast and physically challenging virtuoso piece, because there's so much practice involved.

The Fantasia is considered to be a relatively challenging piece to perform.

Considered a beautiful yet highly challenging piece to perform, it has become a standard of the wind ensemble/concert band repertoire.

"It is an audacious and challenging piece of legislation," he conceded.

There is an ecological message running throughout this riotous yet challenging piece.

It was described by reviewers as a "frighteningly frantic" and "challenging" piece.