Liberty of the Believer has some good points about the link between the Catholics and Tradition (with a capital “T.”)
For all her insistence on doctrinal accuracy concerning matters of faith and morals, [the Church] does not and never has frowned on the luxuriant growth of local customs, imaginative pieties and even legends as long as they do not crowd in upon the essence of her gospel . . .
. . . here in the West, Christians of every stripe sing “We Three Kings” every Christmas and give the names Gaspar, Melchior and Balthasar to the Magi (who number three only in legend). We find our souls nourished by Christmas trees, Advent candles and such sweet stories as “The Other Wise Man” or the Little Drummer Boy. And we find such legendry does no harm to the facts of the gospel. Rather, it is simply an example of the Christian’s perfectly human liberty to tell a good tale, coin a custom and dress out genuine history and theology in the homely cloth of our own woven imaginations . . .
. . . the Church draws a distinction between Tradition and traditions. Tradition (Big T) includes such unalterable items as the canon of Scripture (Scripture, after all, does not say what books constitute the canon so it falls to Tradition to say so), the Trinity, the Resurrection, the hypostatic union, the Real Presence in the Eucharist, the Immaculate Conception and other items of de fide, non-negotiable, dogmatic content.
But small “t” traditions are myriad, and arise not necessarily from the apostolic teaching which the bishops preserve, but from the heart and minds of a thousand cultures and tongues.