Answer:
proactive interference
Explanation:
proactive interference refers to a situation when an old information is blocking the retrieval of the new information.
When you are told to recite the poem, you most likely concentrate to fill your memory with the lines from the poem. So, when you are told to remember the lyric of the song, the lines of the poem will act as the old information that prevent you from effectively processing the new lyric of the song.
This will makes you have more difficulties in recalling the lyric compared to your classmates who was not require to retrieve any information before the lyric.