A report of some of the then Cardinal's views on Church Music can be read here
http://www.catholic.net/rcc/Periodicals ... iller.html
and another summary can be found in Francis Mannion's
Masterworks of God - Essays in Liturgical Theory and Practice (Hillenbrand Books, 2004)
IMHO, these summaries are inadequate tools with which to try and grasp the depth of the theology expressed. Much better to read the man himself (and he is very readable)
A New Song for the Lord - Crossroad Publishing, 1996 - is available in paperback and its new cover (2005) could give the erroneus impression that there is something of authoritative Papal teaching therein (Pope Benedict XVI in bold and gold majuscule followed by a photograph).
It is only a book of spiritual and theological reflection and should be read as such. Read it without any preconceived agenda and without any hint of partisanship.
Somewhat wild press reports about our Pope's intentions to ban guitars in church will then be seen for what they are - sensationalism. For example, in questioning certain aspects of the effects of rock music and its suitability for liturgical use, all that is being said has been said before by figures such as St Augustine and St Jerome in the context of their time and place and the theological problems they were encountering.
Anyway, I commend the book rather than reports/summaries about it.