This site has a great list of appropriate hymns and musical selection for today's feast, including this hymn by Father John Lingard:
Hail, Queen of heaven, the ocean star,
Guide of the wanderer here below,
Thrown on life's surge, we claim thy care,
Save us from peril and from woe.
Mother of Christ, Star of the sea
Pray for the wanderer, pray for me.
O gentle, chaste, and spotless Maid,
We sinners make our prayers through thee;
Remind thy Son that He has paid
The price of our iniquity.
Virgin most pure, Star of the sea,
Pray for the sinner, pray for me.
And while to Him Who reigns above
In Godhead one, in Persons three,
The Source of life, of grace, of love,
Homage we pay on bended knee:
Do thou, bright Queen, Star of the sea,
Pray for thy children, pray for me.
Father John Lingard (5 February 1771 – 17 July 1851), of course, was the Catholic priest who wrote the great eight-volume work The History of England that did so much to overturn the Whig view of English history--or at least to present a more balanced view of the English Reformation.
Before declaring the dogma of the Assumption of the Blessed Virgin Mary, Pope Pius XII surveyed the bishops, asking them for input. The tradition and practice of the Church had long been to depict and celebrate Mary's triumph in Heaven with her Son and because of her Son. In his 16th/17th century Gradualia, for example, William Byrd set the Propers of the Mass of the Assumption of the Blessed Virgin Mary (the Introit, Gradual and Alleluia before the Gospel, Offertory, and Communion). The Cardinall's Musick devoted a CD in their complete cycle of Byrd recordings to his Marian music. As Andrew Carwood noted of Byrd's setting of the Mass for the Assumption:
Byrd produces a vigorous setting for the Assumption Introit, fresh sounding and vibrant with a concentration on the joy displayed at Mary’s arrival in heaven. Once again, Byrd uses triple time to conclude his setting of the Gradual and Alleluia, this time to reiterate the final words of the verse (a rare occurrence) after which he resolutely remains in three until the very end of the movement. The Offertory verse Assumpta est Maria is most remarkable for its final Alleluia which must classed as one of the most imaginative settings of this word ever produced, whilst the Communion Optimam partem elegit is exquisite in every detail.
More on the Feast of the Assumption of the Blessed Virgin Mary and the English Reformation here.