Less intrusive information delivery has been a popular research topic for auditory displays. While most research has addressed this issue by creating new notification cues such as rendering ambient soundscapes or modifying background music, we present a novel method to gently deliver artificial notification sounds that have been commonly used in digital devices and for popular applications. We propose to play a notification sound by embedding it into the music that a user is listening to, after changing the musical timbre, amplitude, tempo, and octave of the notification to match these features of the music. To implement this concept, we extend a melody extraction algorithm for notification timbre transfer, and we present a pipeline that algorithmically selects a proper time spot and harmoniously embeds the notification into music. To validate our design concept, we present a user study comparing our method with the standard method of playing notification sounds on digital devices. Through an extensive analysis of 96 tasks performed by 32 participants, we demonstrate that our method can deliver notifi-cation sounds in a less intrusive but adequately noticeable manner and is preferred by most participants.