Sight reading music on an instrument is not the same as sight reading music for singing. With regards to the instrument, it is the skill of being able to hear a piece in your head and then play it correctly on the instrument. Sight Reading music is being able to vocally produce the correct pitch, intervals between notes and the quality of the note: meaning 1/4 note 1/8 note etcetera. Music dictation is your ability to identify the intervals between two pitches played. For example to identify whether two notes played reflect a fifth, sixth, second, third.. etcetera. Your ability to identify what you hear is a very useful skill. For example if can correctly identify pitch and quality of notes you can transcribe other peoples music for your own playing enjoyment. The attached song is one that my skills in musicianship has helped me to navigate.