Four crossover groups mesmerized fans with fresh, intense music, presenting a bold mixture of genres. "The Masterpiece," a concert featuring the crossover groups Fortena, Crezl, RabidAnce, and Liberante — formed through seasons 3 and 4 of JTBC's audition program Phantom Singer — was held over the weekend at Inspire Arena in Yeongjongdo. The concert began with Fortena, a group of four tenors.

The quartet opened the show with "Neapolis," which the group performed during the Phantom Singer competition. Fortena continued with an intense stage of "Demain n'existe pas," followed by a dynamic arrangement of Schubert's "Erlkonig." The quartet finished with the tender love song "Falling Star" from its first EP "Kingdom," released last December.

Up next was Crezl, a unique ensemble composed of baritone Lee Seung-min, musical actor Lim Gyu-hyung, former idol singer Jo Jin-ho and traditional Korean musician Kim Su-in. The set opened with the rhythmic pop tune "Faith" by Stevie Wonder and Ariana Grande, then shifted the mood with "Forbidden Love," the title track from the group's first EP released in April. The song featured a haunting backtrack, reminiscent of a horror film, with Kim Su-in's passionate traditional Korean singing style blending unexpectedly with the members' classical and pop vocals.

The quartet delivered reinterpretations of Korean pop classics like Shin Joong-hyun's "Beautiful Rivers and Mountains" (1976) and Cho Yong-pil's "Hwang Jin Yi" (1983), for which the audie.