Spiritualists would often provide entertainment at parties or on stage, performing séances to contact the spirits of the dead. Rather than odd mystics and witches, people who presented themselves as doctors or professors would suggest that they had a scientific method for interacting with a supernatural world. Of course, with the wave of rationalism and science becoming a major part of the common person's daily life, the stage was set for pseudoscience - fantastical (sometimes intentionally misleading) beliefs garbed in the trappings of science. Naturally, there were some who felt that all this change was leaving some things behind - the Romantics (who, among others, included Mary Shelley, who wrote Frankenstein - which one could argue is the most important work in all of speculative fiction) sought to bring emotion back into what had become a cold and ultra-rational style in fiction. The enlightenment saw a huge transformation in the way that society was run - people started asking questions like "hey, why is that king allowed to rule over us when all he did to be king was be born into a certain family?" The enlightenment brought massive cultural change, and also powered technological change, which in turn also brought massive cultural change. While belief in ghosts and unseen spirits and demons has been part of human culture since, well, humans have had a culture, the Spiritualist movement of the 1800s was, in large part, a reaction to the age of reason and the enlightenment. "Spiritualism" was a major craze in the 19th Century. Indeed, their beneficial spells can be thought of as just another form of mind-manipulation, only in this case it enhances the subject's capabilities rather than hindering. They can induce a useful mood for their companions while also messing with the emotions and perceptions of those around them - Bards tend not to use big destructive spells like Fireball, but have pretty broad access to mental-manipulation magic. I like to think that a Bard is basically an emotion-mage. But the truth is that Bards are ultimately weavers of stories and lore more than anything else. The typical Bard is usually portrayed as someone who casts their magic and inspires their allies using music - Bards get to use musical instruments as spell foci and they have abilities like Song of Rest that imply their arts are purely musical in nature. Yes, Bards got a new subclass in another setting book - the Eloquence Bard in Mythic Odysseys of Theros - that was reprinted in Tasha's Cauldron of Everything so that it would be setting-agnostic and AL-legal, but the flavor of this subclass plays beautifully into the Gothic Horror theme of Ravenloft. One of the upcoming subclasses in Van Richten's Guide to Ravenloft is the College of Spirits Bard.