Well, the angels might be singing, but I sure know a lot of puppies who aren't listening to them...LOL. For many dog owners living with puppies between 4-6 months of age, this not listening phase is quite frustrating. I'm here to tell you the phase is short (usually a couple of weeks or so), BUT whether your puppy responds to you going forward depends a lot on how you deal with your frustration during this normal phase of their development.
First, let's start with why this "not listening" thing can be seen as a good thing. Your puppy is feeling confident, brave enough to explore beyond the usual boundaries, including the boundaries of your voice and directions for them. Developmentally, this age in wild canids like wolves, coyotes, wild dogs, etc. is associated with the beginning of independent exploration, away from the den and the watchful eye of the dam. For your puppies, it's quite similar; they are looking to explore their world with a bit more freedom and independence than they've previously shown. Those 8 week old puppies that didn't want to let you out of their sight, are now hardly looking back as they explore the far reaches of your yard, or the full length of their leash. So what are you supposed to do when your puppy ignores you? Well, you most certainly don't want to let them get away with that! If you do, that just sets you up for future issues with attentiveness to your directives and overall responsiveness.
When that puppy ignores you, you have to step up your game AND you need to anticipate this behavior before it happens. So, while you might be tempted to let that 4-6 month old puppy roam leash-less in your yard, don't. Put a long line on them instead; this gives them some freedom to explore, but a tether for you to gently tug on if they don't respond when you call them back. You don't want to yank on the line as they'll just resist. Instead, put a small amount of pressure on it and call them. Don't say "come," necessarily, as you don't want to make coming to you seem negative to your puppy. Instead, whistle, clap your hands, bend down and make kissy sounds, etc. all while tugging gently on the line. I like to wiggle my fingers too as that seems irresistible to a lot of the puppies I meet. Even if they are slow to get to you, throw them a tickertape parade with lots of love and some high value rewards as well when they get to you. Now, and this is important, let them wander off again. You see, you want them to understand that coming to you doesn't necessarily mean the end of fun exploration away from you, it just means that they have to check in periodically. If you practice this long line recall every time you take your puppy outside, you can work up to doing the same thing at the park, during a little league game, etc. What this reinforces is that coming to you and checking in is always a good idea. And, yes, sometimes you'll be reeling them in and taking them home, but not every time. Your puppy learns that check-ins are smart, that they don't mean the end of fun, AND that they will always be rewarded for doing so.
I'll just go ahead and say it. Some breeds are better listeners than others. If you have a hound, for example, and they are hot on the trail of a rabbit they just chased into the bushes, no amount of calling or tugging is going to get them out of there. Just go collect your puppy at the end of that line and start again. Some dogs, regardless of age, never can be trusted to be off leash safely. They just don't have reliable recall. Whether that's because they got in the habit of ignoring their owners as puppies and their owners allowed that behavior, or because they are a breed bred for independent thinking, either way, they stay on leash (or a long line) forever, for their safety and your peace of mind. There is no hard and fast rule that every dog has to have off leash time to be a well-adjusted member of canine society. Some dogs, in fact, are just safer kept on leash.
Henley is a good listener. We've worked on the long line and off leash in my own yard. He knows there will be rewards even if he's slow and he's certainly tested that theory more than once. It does help that he has Ozzie who comes every single time I call him as his guide in life. Ozzie can be off leash and out of my sight and if I whistle, he comes running. Every single time. And that's why he's earned off leash time on forest hikes; he's a reliable hiking companion. Whether Henley gets to that level of reliability remains to be seen. He's only 8 months old and he's got a lot of maturation left to do. Ozzie and I are ever hopeful.
As always, if you have questions about your pet's behavior, you know where to find me.
Here's Desi, off leash, at our neighborhood park when he was about 4 years old. He had great recall, always coming back when called. He was never speedy about it, but he always came back, even if there were squirrels, wild turkeys, or people he wanted to greet.