Mainly known by his artist name Saionji Tanaka, ◯P is called such because of his penchant for using "◯" in his upload notes.
◯P is a slightly new Vocaloid producer, having only started uploading February last year. While his primary genre is Vocarock, he has composed songs with pop-ish and even traditional Japanese vibes. Most of his melodies are obviously synthesized, but his guitars are quite nice with an echo-ey effect on them. He mostly composes repetitive melodies, with a sudden rise at the chorus, as is usual of pop and rock songs. The lack of real-sounding instruments might seem a bit of a disadvantage, especially in his choice of musical styles, but he pulls them off, making his songs actually catchy and nice to listen to. His lyrics often talk of every day things, whether romance-related or just related to a person's daily activities.
◯P has only used Kagamine Rin and Hatsune Miku in his solo works and even in collaborative works, he has only tuned them. His Miku is tuned low and solid while his Rin is high-pitched and sharp--typical tuning for both Vocaloids in rock songs.sample songs
(group, tuned for Kagamines)
• Kitai Nante
• Tsukiakari no Yoru, Boku dake no Jikan
• Kimi Shidai no Machi
• Aru Hi no Rikkyou
I honestly do not know much about ◯P, but when I was listening to his songs, I like the certain aura he puts in them, like it's rock, but it's not something that builds up emotions. His songs are more of relaxing, probably because of his solid tuning and muffled, echo-ey guitars. Hanauta is not his solo work, as it involves other Ps, but it's a promising song. For now, my favorite from him is Aru hi no Rikkyou.