"Song 1" is a playful piece that creates a sense of nostalgia and joy. The main instrument used is a Casio keyboard, giving the song a unique and intriguing vibe. The sound is reminiscent of a toy keyboard, enhancing the playful and fun atmosphere of the song. The melodic tunes coming from the Casio keyboard are engaging, and they create a rhythm that's both catchy and captivating. The song is simple yet charming, transporting listeners to a time of innocence and wonder. The Casio keyboard's sounds are played with skill, demonstrating the beauty of combining modern technology with traditional songwriting.