Great image Kettu. if you have more please share, and especially if you have an online link (if there is) to the archive you refer to.
Firstly I am not an expert on devotional music. I don't intend to define a terminology, only to view my personal standpoint. My connection to devotional is more of an artistic and musical interest re own praxis. This, combined w a resonance towards nature being from a small community, pop. ca. 2000, in the Northern hemisphere. Here, nature, its presence and resources have governed economy, culture, psychology, spirituality, plus- for as long has man has been present in the region. Archeology have dated settlements to early stone age, but there where probably nomads before this time.
Devotional for me is connected to spirituality and nature. This, in the form of a person being a generator of occurrence, a living archive (for culture or nature), a lengthing of nature, or as a point of reference for others (living, dead, or to be)- to name a few. To a large degree all examples mentioned fundaments the performer's/artist's own self-annihilation, or sacrifice of own self. The context could for instance be: In direct presentation of a work, or as a carrier/vessel/bridge for the experience/faith/individual he or she narrates; from the past, to the now, for the future. The self-annihilation is effected when the artist is being an extension of what he represents. In this sense, the performer transgresses the performing setting to some degree, just as much as he is handing further the content he is the carrier for. So one can say it is a form of connections between time, generation and space. I find this context highly interesting. Some similarities can be found in transgressive art and noise culture as well. Others can maybe recognize this sense as connected to loosing someone in the family, or being a parent.
This is just my own take on it, very short and generally written. Hope it makes some sense. In overall view I think it is safe to say that there are a multitude of aspects that can define what is devotional, and what is not. Maybe one needs to study and understand the environment and culture form where the actual diamonds originate, in order to have a clear view of what it represents and what its functions are. The history of Asia, Europe, plus are quite different and complex. Personally I don't have the total vista, but I think it is possible to divulge two types of devotional insignias: One that is connected to history, civilization and dogma, the other connected to nature, nomadism and shamanistic culture. At points, at least now in the present, either propositions mixes and dilutes.
Wikipedia states this (a bad reference, nevertheless as an overview to be understood in the context of history, civilization and dogma):
A devotional song is a hymn which accompanies religious observances and rituals. Each major religion has its own tradition with devotional hymns. In the West, the devotional has been a part of the liturgy in Roman Catholicism, the Greek Orthodox Church, the Russian Orthodox Church, and others, since their earliest days. A devotional is a part of the prayer service proper and is not, in these contexts, ornamentation. During the Protestant Reformation, church music in general was hotly debated. Some Puritans objected to all ornament and sought to abolish choirs, hymns, and, inasmuch as liturgy itself was rejected, devotionals. In Eastern and Near-Eastern religions, devotionals can function as communion prayer and meditation. These are sung in particular rhythms which are sustained over a prolonged period to give practitioners a mystical experience.
