Extra Credits raised a good point when he mentioned how the music of games on old systems was more memorable: composers were given fewer instruments to work with (two square wave channels, a triangle wave, and a noise channel on the NES for percussion) and as such they had to deal primarily with melody and make that the most important part of the song. Further, they would often use chords - series of notes played in tune with each other. Plus, chords are easier to sing as it consists of a single melody that is easy to hum. Incidentally, three instruments and percussion was also the structure of a four-piece band, meaning the NES sound chip was designed with this type of music in mind. Chords are more recognizable in a melody because they have greater impact. However, the use of strong melodies has taken a step back in recent years due to the large palette of instruments and options available to composers.
Michiru Yamane’s “Clock Tower” from Castlevania: Aria of Sorrow (here arranged by Jorge Fuentes) provides an exception to this trend, featuring a strong melody common to the Castlevania series and its 8-bit roots that demonstrates this point about chords. Here, the melody is especially punctuated by the use of chords that gain further emphasis in that the last note in a bar is the chord, punctuating the end of the pattern and the beginning of the next. This is very important for the song as it syncs with the setting of the clock tower that keeps time to a steady rhythm. Additionally, the song has not one strong melody, but three layered together – one played on the piano, another on the guitar, and a third on the strings. If you note, there is also a smooth transition, first at 0:36 from piano to guitar with piano fading slowly to the background, then again at 0:45 when strings take over, but the piano can still be heard clearly, albeit in the background. At the 1:10 mark, chords are plainly audible in the strings, and those long notes further punctuate the melody, breaking it into short stops that create a clearly identifiable pattern.
Note one of the other key elements of a memorable tune: repetition. Here, I am not talking about the repetition of an entire melody through loops (particularly as applies to shorter, sub-30-second songs of the early days of videogames), but the repetition of smaller segments. We see this repetition used throughout the entire piece, from the very opening with the mournful piano ticking away time to the guitar’s intricate upward sweeps of eight notes. All of this is easier to see in the XG-MIDI visualization – the virtuosity required of the notes. Pay particular attention to the rising blue notes of the guitar that hit one note below the strings at 1:09.