How can you listen and judge where you are in the music whilst improvising?

Try developing a sense for phrase length rather than just counting the beat.

Try breaking things down to 2 bar phrases with attention to how you "cross the barline." Place the continuous rhythmic flow over the bar line, like these patterns...

Try simple broken chord and scale lines and count out loud. The point isn't to play fast, complex lines. It's to hear the flow of chord changes and the timing of phrases. Rather than just counting beats, you want to get the feel of a 2 bar phrase length whether the rhythm is on the beat, syncopated, or anacrusis (pick up line.)

You can extend the phrase length by prolonging the rhythm mid-phrase.

Two bars...

...can be prolonged to three...

Another example...

Don't try throwing everything and the kitchen sink to the rhythm patterns. Two simple patterns are enough. Use repetition, truncation, and prolongation of those patterns to develop new phrases and build the whole improvisation.

Remember that space is something to use. Rest help shape a line. Pick up lines fill space, but because they are metrically weak (don't start on beat one) they feel like part of a new line. So a three bar line can fill the space of 4 bar simply by using the fourth bar to give a rest to give a clear end to one phrase and start the pickup to the next...

When you think in phrases it seems you naturally start to think more about where you plan to end the line. Instead starting a line and then sort of chase the chord changes, trying to keep up, counting to make sure you don't forget to change at the right time, it's more like thinking 'I'm going to F7, but through C6` or something similar.

Regarding what tones to actually play, keep in mind there are only two basic harmonic categories for this two bar approach: the chord stays the same, the chord changes. Keep things simple. If you focus on the common tone between chords, then only one tone is necessary! If you want to change tones, a single step is usually the only thing needed to make the line follow the chords. So, that's just one tone or two tones to build the line from. You can elaborate those tones with neighboring tones to dress things up. The point in keeping the line simple is to shift the attitude away from thinking melody is all about pitch and feeling how important rhythm is to creating a good line. That should get help you know where you are in the music.

This might sound simplistic, but what works for me is to deliberately favor listening over playing. When I feel myself struggling to keep track of place, I concentrate more on hearing the other players and the totality of the music than on what I’m doing. If I miss some beats, no big deal; better to miss a few possibilities than to play a misplaced note. Metaphorically, focus on the horizon rather than your own two feet.

Also, the ubiquitous sage advice of thinking in musical phrases, rather than notes or scales, helps me better feel the changes and not clutter the mind with counting.

I think you just have to internalise the beat. But I share your propensity to getting lost in the chord sequence. I find having the music copy, or at least a chord chart, in front of me helps a lot. And don't be afraid to play a couple of choruses keeping close to the original melody. (I DO hope there was one? These 'chords only' songs are so boring...)

Improvising over a 12 bar blues has been covered - and basically needs you to know what the format is, so learning the sequence and being able to play simple one chord/note per bar initially works well, moving on only when you are sure of where you are. And on that note, it's absolutely essential that any muso knows where ONE is, and what to play over it.

But what about writing it all out, 4 bars per line, so you can follow it, as you would with words, reading out loud.

With a 12 bar, it's pretty straightforward, but I'm planning for future times, when perhaps you may only have a lead sheet, or a chord chart to follow. When depping, this happens a lot, and it's good to be able to see the next two, three, four bars so you can prepare your phrasing, and decide what notes will fit best, rather than merely playing something over each bar in isolation - which is exactly how it will sound to the listener. One bar at a time can work over a 12 bar, but still it's best to consider your playing over two or four bars, to produce continuity.

That last para. is because whle we may be able to remember a lot of sequences, being able to follow what's written saves any memory loss or glitches! And good players will read through the first verse, and by then it's embedded enough to have the route planned out for subsequent verses.

I think Aaron's answer covers what you need but what I do when I improvise is I actually sing either the chord progression or a bass line in my head when I'm playing rhythm and then when it's time to solo, the chord progression or bass line continues to play in my head when I solo.

I also improvise in 4 bar or 8 bar sections and I've done this for so long that I intuitively know the lengths of these in my head.

I play in a band so if I happen to get lost, I just pause tastefully, listen to where the rest of the band is and then continue along with them. If I look meaningfully at the lead player, she'll usually oblige with a few notes of the melody at the appropriate spot.

32 bars can be hard to keep track of, but if you break your improvising into 8 bar sections, you'll find that it's easy to count to 4 in your head.

The 12 bar blues is a good practice. It seems that you haven’t fully internalized the schema and the bass line:

• Imagine the 3 lines and 4 bars per line. Also be aware of the degree pattern.
• Play first a bass line, sing the line with note names of the triad do mi so
• Write the lyrics of any blues, or invent your own text, sing along the words to the bass line or the rhythmic blues pattern.
• Think in motifs of 2 bars. Imagine an antiphonal theme (question - answer)
• Write down the lyrics as song text in 3 lines á 4 bars (2x2 bars per line), drawing the bar phrasing’s above the lyrics.
• Draw a graphic notation of your 2 bars motifs (just lines swinging up and down) regarding your improvisation idea.
• Write the bar numbers to graphic notations and the lyrics.
• Recognize that the bar 3-4, 7-8, 11-12 are similar or identical, 5-6 is like 1-2 transposed a 4th up or in the minor variant, bar 10 => 9 a 2nd down and a split off frothe head motif.

You’ll find this features in almost every blues. Start with bar 9 and 10, this progression you will always be aware of. Then just add 11-12 with the V7 for the turn around.

• Then play first line I7-I7 (question) I7-I7 (answer)

• second line IV7-IV7 (question transposed) I7-I7 (answer)

• add the well known and already identified V7-IV7 and I-V7 of the last line

Transfer this technic to any other song.

Analogy to poems, 4 bar lines, 2 bar phrases, drawing a mind map, notating a lead sheet, marking the 2 bar phrasing’s, circle of 5ths progressions, bar numbers in 4 per lines, varying 1 single motif in 2 bar phrases (question - answer) or playing only fill-ins.

So for resuming:

write firstly a lead sheet with a clear structure, adding keywords of the lyrics, first play the bass line and the chords, singing along the song - before starting improvising.

Step 1: Play one note per chord, on the downbeat, leaving plenty of mental space to keep track of where you are. Play only the roots, then only the thirds, etc.

Step 2: When you're comfortable with Step 1, continue playing one note per chord, but choose notes that create a smooth line. For example, you might play the 5th of the I chord followed by the 3rd of the IV chord. This is "smooth" because the two notes are only a step apart.

Step 3: Move to two notes per chord, and then add more rhythmic variation. For example, if 4/4 time, start off playing two half-notes. Then try playing on the "&" of one and on 3.

Next steps: As you develop, you can create your own variations on this exercise. Always keep in mind that the goal is to practice knowing where you are, not to play an interesting improvisation. You want your "improvisation" to be simple enough that you can stay focused on where you are.

Further steps: Other more advanced ways to practice this same exercise are to run scales for each chord starting from the root, then run each scale fluidly into the next, run arpeggios, etc....

Just know that as you practice, you're also training your ear to hear both the chord patterns and how your note choices relate to them. Over time, this will become more intuitive.