2. Play the root note of the chord: This will harmonize with the vocal melody. If you have trouble finding the root note in a complex chord, don't be afraid of sticking to the root notes of more straightforward chords (such as G, C, or D), which can still support the vocal part even if the guitar part is playing additional notes.
3. Add embellishments: Once you've mastered playing the root notes, you can start to add embellishments like passing tones or short melodic lines. These can help to add interest and support to the vocal part, but be sure not to overwhelm the melody and drown out the vocals.
4. Listen and adjust: Pay close attention to how your bass part fits with the other instruments and the vocals. If something doesn't sound quite right, don't be afraid to adjust your playing. The goal is to create a balanced and supportive sound that complements the vocal group.
5. Practice, practice, practice: The more you practice playing bass with a vocal group, the better you'll become at identifying and playing the appropriate notes. Listen to recordings of vocal groups with bass backing to hear examples of how it should sound, and don't be afraid to experiment with different styles and techniques until you find your own unique voice on the instrument.