Musical sound interfaces diverse in their tonality and pitch were employed to investigate the influence of emotions on contextual interpretation; two empirical studies using smartphone platform were conducted. The measured appropriateness of the interfaces for several purposes revealed the influence of emotions on the perception of context, with significant relation between the interfaces’ emotional qualities, which were rated in terms of pleasure and arousal, and perceived context represented by appropriateness. In addition, the contextual attributes of the interfaces measured by verbal estimation were shown to be correlated with the sounds’ pleasure and arousal. Throughout the studies the effect of emotional qualities on musical interfaces contextual attributes were verified, meanwhile the implementation of findings required further explorations.