I've just finished this horror anime titled "Mononoke" (モノノ怪). What drew me to it was the prospect of seeing a lone character, who in this case is only known as the Medicine Seller, exorcising yokai/ayakashi/mononoke with a blade that can only be drawn once this mystery man knows the Form, Truth, and Regret of the entity. With a plot that intriguing and the art style being nothing I've ever seen before in an anime I decided to give it a go. "Different" was the word I saw being used to describe "Mononoke". That person was not wrong. Personally, I'd describe it as colourful, eerie, cryptic, and mind-warping. The thought, "What just happened?" popped into my head several times and I had to go down to the comments section to clear my doubts. However, I also found myself staring at my laptop's screen with eyes wide open and my breath held in anticipation when the intense story arcs unfold and when highly unsettling imagery is shown. I wish there was more than 1 season.
Anyway, throughout the series' 12 episodes the theme song used was "Kagen no Tsuki". With the most of the story arcs and designs being set in the Edo period, I assumed that the opening theme would represent that by sounding traditional - with instruments like the shamisen, taiko, shakuhachi, etc. And it did fool me into believing so during its intro. Though what I first thought was the accordion was being played, there was also the tinkling of some Japanese string instrument - sounds like the koto to me. Then when the name of the anime was shown, that was when the pace jumped in speed and the tango-esque rhythm kicked in with more Bandoneon (something like the Spanish version of the accordion commonly used in tango music) and Spanish/acoustic guitar. Composing this unique score was Ryouta Komatsu (小松亮太), a Bandoneon player. Reading his J-Wiki profile, he's prominent and established in the world of tango music and has collaborated with multiple artistes like the formerly-glamorous Kenji Sawada (沢田研二) and violinist Taro Hakase (葉加瀬太郎).
Singing "Kagen no Tsuki" to Komatsu's melody is Charlie Kosei (チャーリー・コーセイ), who had provided his smooth vocals for the theme songs for many installments of the "Lupin III" series. He delivers "Kagen no Tsuki" in a somewhat laid back manner, though some parts sound quite odd like he's hopping from one word to another.
"Kagen no Tsuki" was released in 2007, which was also when "Mononoke" was released. Despite this tune being seemingly out of place in "Mononoke", I find that it blends quite well with the atmosphere of the anime and sets the tone for it. It's also a little creepy especially when combined with the visuals from the opening sequence.
Just some trivia to end things off - voicing the aloof Medicine Seller, whose speech is slow and halting, was Takahiro Sakurai (櫻井孝宏). For those who watch "Shirokuma Cafe" (しろくまカフェ), you'd probably recognize him as the voice of the coffee-serving Shirokuma.