Video source: Seven News.
In the video the Cathedral Choir is singing the Introit for the 11th Sunday of Ordinary Time, Exaudi Domine. They also sang the proper Alleluia, Domine, in virtute tua laetabitur rex, and the Communio, Unam petii a Domino. There was a responsorial Psalm in English, and the Offertorio was polyphonic. There was only one hymn, sung post-Communion. See the music list here.
I was reminded of what two Austrian priests visting the cathedral in Sydney in 2010 commented to me. They had just concelebrated a Mass during Ordinary Time (like the one in the video), and had marvelled at the solemn beauty of the Mass. They lamented that the Austrian Cathedrals were good on High Feasts, usually with choirs and even orchestras being brought in for the occasion, but in between the music was altogether lacklustre. I cannot comment on particular churches in Austria, but I can certainly imagine what the priests meant. Relatively speaking, there are not many Catholic cathedrals in the world today that have a trained choir dedicated to singing the Church's liturgy (and year-round), despite all the exhortations concerning sacred music throughout the first half of 20th century and emphasised in the documents of and following the Second Vatican Council. In Australia, the Cathedrals in Melbourne, Parramatta and Sydney stand out. There are others with choirs, but I am not aware of any that draw upon the Church's rich muscial patrimony as earnestly as the aforementioned.
Oh, and if you are going to have an orchestral Mass, you may as well do it the Köln Cathedral way! Here is that Cathedral's resident liturgical choir singing the Kyrie and Gloria from Haydn's sumptuous Harmoniemesse for Whit Monday (Pfingstmontag) 2012, an holy day of obligation in Germany. Veni, Sancte Spiritus.