Area2 Basic is most prominently featured in the large cavern in Area 2 containing the apparent ruins of a Chozo hydroelectric power station. It also plays in some of the tunnels branching off of the large cavern, and in some of the upper rooms of the ruins interior.
This theme has a somewhat "industrial" feel. Much of the melody is performed by a high-pitched flute-like synth, which fluctuates downward and upward. It also prominently features echoing percussive beats, metallic clanging, a catchy bass guitar line, and effects that simulate the sound of dripping water. While the high-pitched melody seems to emulate the style of the ambient tracks of Metroid II: Return of Samus, this song appears to be an original composition by Daisuke Matsuoka and is not clearly based upon any of Ryoji Yoshitomi's compositions.
Area2 Basic can be heard here: