#technical archivism

My tape recorder dislikes music. I am yet to test if this is with all digital recording, but it is strange because the first few seconds of the music I record are intact while the rest are slowed and deepened. This is true even if the digital music is a higher distance away than my main voice. I know it is not damage to the tape because I can record over it well. I am curious as to why short lengths of music are okay and why it distorts that heavily. I find this peculiar.