The Supreme Court has upheld the lower court's rejection of Johnny Only's claim that the Pinkfong Company's song "Baby Shark" infringed his copyrights and dismissed the American composer's appeal. 

The songs at issue were both based on a nursery rhyme originating in North America ("Subject Nursery Rhyme"). The key issue in dispute was whether Johnny Only's song warranted protection as a distinct derivative work. For a work to be protected as a derivative work, the court noted that it must "maintain a substantial similarity to the original work but have been creatively modified or altered to the extent that the work can be recognized as a new work in view of social norms." 

In the court of first instance, Johnny Only argued that he had made distinct creative changes to the original song by using different melodies from the Subject Nursery Rhyme, adding new rhythms, using different harmonies and new instruments, example. However, based on an appraisal provided by the Korean Copyright Commission in response to a fact inquiry, the lower court held that Jonny Only's song could not be recognized as a new work since its level of creativity was relatively weak overall, even though there were some parts that were unique. The Supreme Court agreed with this view. 

The Supreme Court's holding reaffirmed the existing legal principle that a work cannot be regarded as a unique (derivative) work and protected under the Copyright Act, if only minor modifications or adjustments have been made to it. 

As to the credibility of the Korea Copyright Commission's appraisal which was disputed by Johnny Only, the Supreme Court's position is that unless there was a substantial error (due to the method of appraisal being unreasonable or against established practices, for example), the results must be respected. Applying the above standard, the lower court held that Johnny Only's argument that the Korea Copyright Commissions' appraisal results could not be trusted had not been sufficiently substantiated. 

Since Johnny Only's claim of copyright infringement could not be established without his song being recognized as a derivative work, the Supreme Court did not separately assess whether the Pinkfong Company's song was substantially similar to Johnny Only's song and infringed his copyrights.