Is it just me, or are the bard help files excessively vague?

The repertoire help files make it sound as if comedy is generally the opposite of tragedy, which makes sense, and that romance is generally the opposite of epic. Most of the songs follow that pattern. If a help file describes a song as favoring comedy, then it usually disfavors tragedy and is "neutral" along the romance/epic axis.

Several of them seem to buck this trend, though, if I'm reading the help files correctly. Symphonic echoes, for instance, seems to be pro-comedy and anti-epic. Dirge of solitude seems to be pro-tragedy and anti-romance.

Does the fact that echoes is pro-comedy necessarily mean it's also anti-tragedy, even though the help file only describes it as being anti-epic? Or is it "neutral" to romance/tragedy?

Preface: this is the sort of thing I would normally post on Dio's, but I'm going to try posting here from now on.

Here's a list of the bard songs, with apparent favored and disfavored repertoires listed.

traveler's march: none
charismatic prelude: +romantic
adagio: +comedic -tragic
piercing dissonance: +epic -romantic
chant of resilience: +epic
battaglia: +epic
canticle of the gods: +romantic -epic
elven adagio: -epic
lullaby: +romantic -epic
languid carol: +tragic -comedic
anthem of resistance: +epic
riddle of revelation: none
cacophonous clamor: +comedic -tragic
reveille: +epic
pastoral of the mind: +romantic -epic
tranquil serenade: +romantic -epic
requiem: none
elegy of tears: +tragic -comedic
bagatelle of bravado: +epic
laborious lament: +tragic -comedic
vibrato: +epic
nocturne of fright: +tragic -comedic
apocalyptic overture: +epic
fantasia of illusion: +romance
symphonic echoes: +comedic -epic
dirge of solitude: +tragic -comedic
grand nocturne: +tragic

So, some questions:

Songs like Vibrato and Grand Nocturne are clearly described as favoring a particular repertoire. However, neither song is described as suffering a penalty when sung by any of the other repertoires. Is that really the case? For instance, would vibrato be as potent in romantic as it would in tragic? Would grand nocturne be as potent in comedic as it would in epic? Or, is it fair to assume that if a song favors one repertoire then it necessarily disfavors the "opposite" repertoire?

Symphonic echoes is odd in that it favors comedic but disfavors epic, where those two aren't opposites. Am I reading that correctly?

A song like Riddle of Revelation seems to favor no repertoire at all. Is that the case? Are any of the other songs "repertoire neutral"?