Macbeth is one of the best theatrical studies of the relation between power and corruption. It portrays the darkest side of politics, something that is inherent to human nature and society, independently of time and place.
Verdi loved Shakespeare and Macbeth came to be one of his favorite operas. It is the most powerful and dramatic work of his youthful compositions. The music is gorgeous, the demands on singers/actors are enormous. Simply a masterpiece, one of the most appreciated in recente times.
In this film we have some of the best singers who ever performed these roles. Shirley Verret's performance is historic, she dominated this part better than anyone. Leo Nucci is another verdian icon and he was in top form at the time of this register. The other interpreters are also excelent.
The film is very well done, dark and scaring. It is not easy to make a good opera film but this is one of the success cases.
In conclusion, I consider it higly reccomendable. Enjoy!