Hi,
I wouldn’t worry too much about it. I’ve heard that Crucial Music has a rejection rate of around 80%. It happened to me as well—I submitted songs that had won the German Songwriting Awards and the UK Songwriting Contest, both of which were very mainstream pop. And they rejected them without a second thought.
I think Crucial Music is one of those libraries that looks at what they already have in their catalog. They probably have enough pop songs at the moment and are looking for something else. For example, I heard about someone who submitted ten singer-songwriter tracks, and six of them got accepted right away. So I really think it’s more about what they need at the time.
Also, their contracts usually last three years, and they seem to make a real effort to place the music they sign. They’re not just stringing people along, which is great. So I truly believe it’s more of a portfolio question rather than a reflection of the quality of your music.
If you’re interested in working with them, I’d just keep submitting music. At some point, something will stick!