Sampled Term Frequency vs. Global Term Frequency

This is kind of related to this post here.

Say I have a sample of 100 artists, and I take the average term frequencies for rock, pop, and hip hop, and normalize against the average frequency for rock among this sample. Can I then compare these figures to the global term frequencies for rock, pop, and hip hop and reach conclusions along the lines of "the sample of 100 artists has a higher concentration of pop-artists relative to rock-artists than the global population because the sampled (and normalized) frequency for pop is higher than that of the global (and normalized) frequency for pop". Or am I somehow misunderstanding how artist term frequency and global term frequency are related?

Thanks in advance.