Strangely, those who are not old enough to have lived when TLH was in its prime are the ones who seem most nostalgic for its heyday. I have written before that because they did not grow up or live as adults in the era when TLH was the hymnal for our Synod and the Common Service more common among all Lutherans, they do not realize the inadequacies and lacking of that era. Clearly, however, the push to recover a common liturgy and common doctrine is not nostalgia -- the boomers who can recall these days tend, as a group, to be moving in an opposite direction. Neither is it quite nostalgia among those who cannot recall the origins but who can appreciate the blessings of unity in liturgy and dogma. What might be more appropriate is a deep sense of reverence, even awe, for the presence of God and the things of God.
Admittedly, it does not quite work to make TLH casual. Forms had to be invented to supplant that book if a casual, God my buddy style of worship and music was desired. Unfortunately, all the sins of this perspective get blamed upon the modern liturgical movement. That is not quite true, either. While it is fair to say that diversity and an embrace of local culture and the domain of preference left the door open for the worship band and diva and the love songs that imagine Jesus who is no longer present sacramentally, neither Vatican II nor the modern liturgical movement that attracted Lutheranism was about abandoning reverence. It was more about making the forms more accessible, to be sure, and more united (all in one book for Lutherans), but it was also about restoring a profound sense of baptismal life and identity, a hunger and yearning for a Sacrament that then was celebrated monthly or less, and the rediscovery of the sacrament of absolution within the life and piety of the people and their pastors. The problem for Rome was that Vatican II's direction was replaced by the personal goals of Annibale Bugnini and a distracted Pope Paul VI who rubber stamped his radical reforms. The problem for Lutherans was far different. The work of the liturgical movement and a common hymnal got hijacked by the radical cultural shift within America, the battle for the Bible, and the maturation of a thoroughly American form of Lutheranism more at ease with itself than it had ever been. Put that all together and it is rather remarkable that the worship reforms of the mass were as tame as they ended up being -- certainly more moderate than some of Missouri's own experimenting in Worship Supplement (1969) and the first editions of the ILCW trial offerings. In fact, looking at ELW and what happens among the evangelical wannabes of Lutheranism, even LBW seems thoroughly serviceable in hindsight. But when they appeared and later LW, the break with our past dominated and, at least for Missouri, created a window for TLH to live on in practice but most of all in our dream of a more pristine and ordered past.
What those under 40 are looking for is radically different than their parents and grandparents imagined from the liturgical reforms of the 1960s-1970s. They are not nostalgic as much as they are panicked by a piety that seems plastic and worship that is self-serving and self-referenced. They are looking not for something from the past but something in a continuum with that past, a deliberate reform that marked a hermeneutic of continuity that has made even more attractive the Latin Mass among Romans and the Divine Service out of the Common Service tradition among Lutherans. They are searching for authenticity, reverence, transcendence, and, most of all, integrity among the preaching and the liturgy. You cannot blame them for nostalgia but you can blame those who used the moment of reform to introduce an alien spirit into the Divine Service, stripping it of all that had made worship distinctive and therefore God's work. The nostalgia of those for folk rock and soft rock has taught their children and grandchildren to look for something different than their families desired and this has led them to look all the way back to 1941 in Lutheranism and the 1950s in Rome.