I think "the needle" is the needle on a record player. She's often sung about the connection between music and memory (Guided by Wire) and memory and loss (Star Witness, South Tacoma Way). Here, she's stuck in traffic, watching the planes fly low, and something happens to make her remember her past as a young girl in WA. Planes are also a trigger for memory (Maybe Sparrow) in her songs. When the "needle" lands on a record player, the song begins to play; here, her past, with its regrets ("if I knew then what's so obvious now, you'd still be here...") comes back.
I think "the needle" is the needle on a record player. She's often sung about the connection between music and memory (Guided by Wire) and memory and loss (Star Witness, South Tacoma Way). Here, she's stuck in traffic, watching the planes fly low, and something happens to make her remember her past as a young girl in WA. Planes are also a trigger for memory (Maybe Sparrow) in her songs. When the "needle" lands on a record player, the song begins to play; here, her past, with its regrets ("if I knew then what's so obvious now, you'd still be here...") comes back.