Lots of my friends think that Prince's music is old, but I think it's not only excellent but also an innovation.

The problem is in the second half of the sentence.

In a "not only ... but also ... " construction, you need to make sure the wording that follows each part is the same as the other. In this case, this is what's there:

not only excellent ("excellent" is an adjective)

but also an innovation ("innovation is a noun)

So ... revise so both are adjectives or both are nouns. How will you do that?

Lots of my friends think that Prince's music is old, but I think it's not only excellent or but also an innovation.

It's great that you appreciate Prince's music and recognize its innovation! To address your friends' perception, it might help to provide them with some background information about Prince's contributions to the music industry.

Prince, whose full name was Prince Rogers Nelson, was a highly influential musician, singer, and songwriter. He rose to fame in the 1980s and continued to create music until his death in 2016. His genre-defying sound combined elements of funk, rock, pop, R&B, and soul, creating a unique blend that set him apart from other artists of his time.

One way to explain Prince's innovation is by highlighting his musical style. He often incorporated unconventional instruments and sounds into his songs, pushing the boundaries of what was considered mainstream at the time. For instance, Prince was known for his virtuosic skills on the guitar, which he showcased in iconic songs like "Purple Rain" and "When Doves Cry." He also experimented with electronic music, using synthesizers and drum machines to create futuristic sounds that were ahead of their time.

Another aspect of Prince's innovation lies in his lyrical content. He addressed social and political issues, sexuality, love, spirituality, and personal identity in his songs, challenging societal norms and expressing himself in a bold and provocative manner. This willingness to tackle taboo subjects and push boundaries played a significant role in shaping the landscape of popular music.

To further support your argument, you can introduce your friends to some of Prince's most well-known and acclaimed albums, such as "Purple Rain" (1984), "Sign 'O' the Times" (1987), and "1999" (1982). These albums not only showcase his musical versatility but also highlight his songwriting prowess and ability to craft catchy melodies that have stood the test of time.

In summary, Prince's music is not only excellent but also innovative. By explaining his unique sound, willingness to address taboo subjects, and his influence on the music industry, you can help your friends understand why his music remains highly regarded and relevant today.