In the practice of Catholic theology there is an ongoing issue as to how one might successfully achieve being faithful to the tradition--respecting the great patrimony of thinkers of ages past--while also being genuinely contemporary, bringing into play authentic contributions from the modern/post-modern world. (For a related earlier post see here.) The best Catholic theologians I think always strive to do both.
I think that an instructive parallel can be seen with music, especially in live music that includes individual solos against a background of a standard tune.
Think of how this works with a live jazz performance (bluegrass would serve just as well). The whole group of musicians launches into a particular song (e.g. "Devil May Care" as below with Diana Krall and her band). If it is a jazz standard, the song has a traditional structure and melody. Its basic foundation is known--solid, stable. And because the musicians are accomplished, well-practiced, and also know the song well and know how they like to play it as a group (since they have rehearsed it), the foundation of the song's basic structure is secure during the live performance. No one has to worry about the song going off track or anyone getting lost as to where the group is in the song. This provides the context for each individual musician to then be able to stretch his wings and shine in various solo contributions as the song is performed. Each soloist can challange himself more to his highest potential as a soloist knowing he can lean upon/rely upon the secure foundation maintained by his bandmates. You can see this taking place among great musicians as they perform live--the security of the known providing a base upon which the creative can soar without fear. [Less accomplished musicians cannot do this well. They are not secure enough in the basic elements of the music to allow for each soloist to flourish to his full potential.]
With the steady, secure foundation of the rest of the band moving along confidently the stage is set to permit the musicians to take turns shifting out of the role of being part of the supportive musical backdrop, "stepping out" into solo roles. Then, after a solo stint they seamlessly shift back into the group's communal performance of the standard song structure, allowing another member in turn to step out for their solo and then back, and so forth, in a flowing, creative back-and-forth between the song as performed by the group and moments of individual creativity and spontaneity.
And a further observation about how this works: As each musician takes a solo turn, they do not do so as though they were detached from the underlying song structure being played by their fellow band members. Very often, the underlying standard melody to which they are all together attuned and "locked in" as a living community in a united dynamic action, provides creative raw material for the soloist to riff on--augmenting, twisting, inverting, playing with the known melody to put his own unique interpretation on it.
So, it is not by acting as an isolated, lone agent that each soloist creates his own special musical contribution of the moment to the living whole. Rather, he makes his solo contribution by allowing it to somehow shadow, reflect, interpret, and build upon--but in a unique and unforeseen way--the known and predictable form that the others are playing underneath. This playful interaction between the known tradition and the creative output of the moment, informed by years of practice and talent development, makes for the occasion of a great live music performance. It is undergirded by the secure familiarity of the known and beloved, while at the same time made refreshingly alive and exciting by the transformation provided by the creative and the new.
Good theology is very much like this! It is a musical interplay of the tradition with contemporary and creative elements. And it is the very presence of the perennial in the contemporary that enables the new to have confidence as it breathes new breath and stretches its wings beyond what has come before.