Have drones helped you become better at hiting the correct notes/pitches? I have used drones for O store Gud: https://images.squarespace-cdn.com/content/v1/5b11858da2772cf01402ee6e/1547759943157-AODNZKK5OGUEBO53JTUB/ke17ZwdGBToddI8pDm48kI6q7B9tf9c6VtLCeFT-t657gQa3H78H3Y0txjaiv_0fDoOvxcdMmMKkDsyUqMSsMWxHk725yiiHCCLfrh8O1z4YTzHvnKhyp6Da-NYroOW3ZGjoBKy3azqku80C789l0iy8Rj2bPXFyaluz0PeKicNFGYomvZfxsIgP60FRf7j6OJD8VZTBXF1BLzaggdI9Iw/HowGreatThouArt01-1955a.jpg

For the first phrase I played the tonic (C in my case as this is an easier key) and sang the melody. Singing with drones seems like a good idea for learning to hit the right notes/pitches. Have you tried this technique? Did it help you? This tune is actually based on I-IV/V-V and for this you bassically only need two drones (C and G if you sing it in C major).