Looking through the quadra music threads, I tried to identify commonalities in musical style.
Vocals in Te/Fi music seem to drift very far away from normal speaking. A wailing style of singing, very unusual speech flow, or distorted voices are common. Lyrics are often hard to understand at first listen. Vocals in Fe/Ti music seem like ordinary speech fit to a particular melody and rhythm, they tend to be easily understandable and carry a more normal range of emotional expression. This difference seems like the familiar Fe polished expression versus Fi raw expression, but taken to an extreme. Since Fi vocals are freed of the normal demands of conversation, they can progress towards an even more pure and unrestrained emission of internal experience. Fe vocals, on the other hand, maintain an speech-style intentional emotional expression that comes through separately from the emotionality of the music itself.
It seems like a lot of Ne/Si tunes are written around the main melody, with other components of the music there to support it. The melody will be singular, clear, and often deliberately catchy. In many Se/Ni leaning tunes, the melody sounds incomplete by itself or competes with other components of the music. It's possible that a clear melody fits into one ready-made conceptual unit in the way Ne and Si accept and process information, with more diffuse melodies fitting Se/Ni style processing as a continuous and textured stream.