To learn singing like Irving Mills, here's what you need to do:

• Focus on breath support: Good breath support is essential for achieving a smooth and continuous sound. Use Singing Carrot's Breathing basics and Breath Support resources to work on this.
• Develop head voice: Head voice is critical to achieving the kind of richness and depth that Mills was famous for. Practice regularly with Singing Carrot's Sound in Head Voice and Head Voice Exercises guides.
• Focus on phrasing: Mills was known for his perfect phrasing, using varying dynamics to create different emotions. Singing Carrot's How to learn a song effectively article and Perform Like a Pro tutorial provide guidance on improving phrasing and techniques to create mood.
• Practice voice projection: A good baritone voice requires understanding how to project voice properly. Start with Singing Carrot's Chest Voice Explained video to work on this.
• Extend vocal range: Although he was primarily a baritone, Mills had an impressive vocal range that allowed him to reach some high notes. You can work on expanding your vocal range with Singing Carrot's Vocal Range Test, and Pitch Training resource.
• Performance techniques: To perform like Mills, you need to understand performance emotions, stage presence, how to overcome stage fright, how posture affects your singing, and how to deliver your performance in an emotionally charged way. Singing Carrot's Tips for performing and stage fright articles provide plenty of advice on all of these topics.

By incorporating these techniques and taking time to practice and develop your voice, you can learn to sing like Irving Mills. Don't forget to check out Singing Carrot's Educational Singing Course to increase your knowledge of singing theory and practical tips, as well as their Song-book and Artist vocal ranges collection to find songs to showcase your Mills-like vocals.