Questions on HW4-Spring07

Questions on HW4-Spring07

Example diagram of resultant list structure
Uploaded Image: HW4example.JPG

Question: Do you need to use song phrase? Or can you create your own class from scratch since technically you don't need it I don't think.

You are required to use SongNode and SongPhrase. -Dawn Finney

Question: Can I have my class inherit SongPhrase since if I use the song I'm using it'll completely tear apart the class? Or is it cut and dry and SongPhrase MUST be used. =\

You might want to email Prof. Guzdial or the head TA REMOVEDel about the inheritance part. I don't really know how you could tear apart SongPhrase since you only going to be adding new methods to it...-Dawn Finney
Or email your own TA. But the answer is YES, you MUST modify SongPhrase and turn in your modified SongPhrase. Mark Guzdial

Question: Oh I'm basically writing a song from scratch that I arranged awhile back I'm basically returning my own phrases to use since I have the song all divided out to repeat and weave. Also if I don't use songphrase will my code not compile and is there a way to change the tempo of nodes? One other question heh, is there a way to do chords with nodes?

You need to use SongNode and it needs to use SongPhrase. You could probably get away with extending SongPhrase but like I said you've got to check with someone higher on the totem pole. I'd check out AmazingGraceSong2.java in your javasources folder for useful sample code. For changing the tempo, it's
```
Score myScore = new Score("Amazing Grace");
myScore.setTempo(100.0);
```
I think that .java file also shows a possible way of doing a chord. -Dawn Finney
No, you can only change the tempo of a score, not a phrase. (Think about it from a music perspective – you can't change tempo for each phrase of music. No orchestra could play it.) You must use SongPhrase. Must. Sorry. Check out the end of the structuring-music.ppt where we create a tree of SongNodes with two linked lists in parallel in order to create chords. Mark Guzdial

Question: If I use song phrase can I make new methods?

You HAVE to use SongPhrase (how many times do I have to say this). You going to have to add to new methods to SongPhrase. HAVE TO!. -Dawn Finney

Question: Is it alright to modify SongNode?

Yes, but you've got to turn it in if you do. I'd recommend only adding additional methods. You don't want to kill the basic functionality of SongNode. -Dawn Finney

Question: When you're writing a midi file, I believe the code is Write.midi(score, "NameofScore.midi"). Where does the midi file go once you write it? In other words, where does Dr. Java save the file?

Since you have to use showFromMeOn(), you'll get GUI window with all of the notes displayed on it. Then you can click File->Save as a MIDI file and choose the name of the file and where you want to save it. I'll check the JMusic documentation and see how you would go about this if you were to code the saving part yourself. -Dawn Finney
It's actually Write.midi(score, "DirectoryNameandNameofScore.midi"); so something like Write.midi(score, "C:/DawnsSong.midi"); should be good. I forget if it you just gave it something like DawnsSong.midi excluding the directory if it gives you an error or saves it to the current working directory. Go experiment. If your computer crashes, sorry. -Dawn Finney

Question: In class, we spoke about using the idea of Node1.next.~ in order to access repeated nodes without names; but when I try this, I find that the copied node is private to SongNode (i.e. .next has private access in SongNode). Should I just edit SongNode or is there a better way?

Use node1.next(); Using node1.next can only be done with public variables. -Dawn Finney
By entering "()", you're telling Java "This is a method that I'm calling – go execute it." Mark Guzdial

Question: My aim is to set the next node of a repeated node; node1.next(); just calls the node in question, but does it allow you to modify it? Thanks for your help, Dawn.

node1.setNext(); Glad to help. -Dawn Finney

Error adding note list: Possibly the wrong number of values in the pitch and rhythm array.

So, I took soundphrase and copied the method of riff2, changed some of the variable names, and then reused it. When I change the notes up for the modified riff2 (as a unique phrase) i get the error above. Also,I basically set the node1's next to node2, node2 to node3, and so on. I don't know why I get this error. Please provide some insight if possible.

```
  static public Phrase riff2() {
     double[] phrasedata =
     {JMC.D4,JMC.EN,JMC.C4,JMC.EN,JMC.E4,JMC.EN,JMC.G4,JMC.EN};
     
     Phrase myPhrase = new Phrase();
     myPhrase.addNoteList(phrasedata);
     return myPhrase;
   }
```
I take it you changed some of the data within phrasedata and the numbers are probably not within the range of numbers JMC uses. I recommend you change the numbers with phrasedata. I can't think of anything else right now unless I see your code. -Dawn Finney
Another possibility is that you miscounted somewhere and you don't have an even number of entries in your array: You need two (a pitch and a duration) for each note. So, the number of items in the array should always be even. Mark Guzdial

Question: My notation viewer is opening up okay when I run my program, but when I choose "Play All" I don't hear anything. I see comments in the Interactions Pane saying that the MIDI music is playing, and more when it's done, but I'm never hearing anything. What gives?

It sounds like there's something wrong with your computer's ability to play MIDI. Can you make your computer make any noises at all? Check that your speaker isn't muted. It could be that something has broken with Java's ability to play MIDI on your computer. To check that, use the menu in the notation view to save as a MIDI file. Go double-click on the MIDI file – Windows Media Player should open and you should hear your song. If it doesn't and you don't, then MIDI has broken (maybe been deleted?) on your computer. A cheap and easy fix is to download QuickTime from http://www.apple.com/quicktime. It's free, and QuickTime does include a MIDI player. Mark Guzdial
Frankly my computer does the same thing from time to time. I usually just recompile and rerun the program until it works. Sometimes when it does work, I hear this scratchy, static filled version of whatever was supposed to be played. Follow Prof. Guzdial's advice about checking whether or not your computer plays MIDI files. If your computer ends up to be like mine, I personally wouldn't worry too much about it. -Dawn Finney

Question: I have a question. So, if I use node3.weave(node1,1,2) means copy node1,one times, after skipping two. I tried looking back at the code and my interpretation is that my structure would look like this: 1,2,3,1copy, 1copy,4,5,1copy,1copy, assuming that nodes1,2,3,4,5 were created in that order with one following the other. Is this correct? Additionally, these copied nodes do count as one of our 10 nodes right?

I would check out dissecting weave powerpoint by yours truly. I'm fairly sure that my examples are correct unless Prof. Guzdial made any changes to weave since last semester. Yes the copied nodes do count in your required 10 nodes. Dawn Finney

Question: How do I add sharp notes to a riff, what's the notation?

Normal: C4 Sharp: CS4

Question: Dawn, do you have any ppt as to how repeatNextInsert works (the weave one was helpful). This is my general question, so if you have a node 1, 2, 3, 4, 5, in that order, and then i do node1.repeatNextInsert(node5,2) i would get 1, 5c,5c,2,3,4,5. but then, if i want to do node3.repeatNextInsert(node4,2)i would get 1, 5c,5c,2,3,4c,4c,4,5.

repeatNextInserting() works just like repeatNext(), only repeatNextInserting() preserves the rest of the list. (Let's use node3.repeatNextInsert(node4,2) and 1->5c->5c->2->3->4->5->null as our list for an specific example to help explain the definition) repeatNextInserting() inserts the specified node (node4) after the node it's called on (node3) the inputted number of times (2). Our final list ends up like you said it would as 1->5c->5c->2->3->4c->4c->4->5->null. Dawn Finney

More Examples

Original List:
node1->node2->node3->null
List after we call node1.repeatNextInserting(node4,3);
node1->node4->node4->node4->node2->node3->null

Original List:
node1->node2->node3->null
List after we call node1.repeatNext(node4,3);
node1->node4->node4->node4->null
Notice how the rest of the list gets lost.
-Dawn Finney

Question: What does this error mean:

NullPointerException: 
  at Song.show(Song.java:43)
  at MyWovenSong.main(MyWovenSong.java:44)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
  at java.lang.reflect.Method.invoke(Unknown Source)

I'm guessing you didn't set the second SongPart. You really don't need to mess with any of this though. You should only being using SongNode and SongPhrase. Dawn Finney

Question: Since we are making a new class in SongPhrase, does that mean we have to start it all the way at the end of the existing class? As in past the closed bracket } ? and if so do we have to type in the import jm.music stuff above our class again?

Just create a new file to hold the new class MyWovenSong.java seems to be a popular choice. Dawn Finney.

but I thought we had to have it in SongPhrase? Has that rule been retconned now? lol.

It was never supposed to be in SongPhrase.You're suppose to turn in to WebCT: (1)Your song class; (2)your modified SongPhrase class; (3)if you end up modifying SongNode or SongPart, you can include that, too; (4)a picture of your resultant list structure. Notice how (1) and (2) are distinct. Dawn Finney.

gotcha.

Question: Where can you find exactly how to manipulate JMC. I want to know to do things such as make the clef treble instead of the default bass. I also don't know the codes for slurs and things like that.

That's really beyond the scope of my knowledge but I found this tutorial online and here is a JMusic javadoc. Dawn Finney.
Don't worry about it. JMusic doesn't have explicit slurs that I know of. Treble clef shows up when the note goes too low, by default. But don't sweat the notation – sweat the linked list. Mark Guzdial

Question: When is our homework due - Friday at 7, or Monday at 10? The announcements page says it's due Monday at 10 so we can ask questions in recitation - is this true? Thanks.

I think you're reading the wrong part of the announcements. Today at 7, grace period to midnight. Mark Guzdial
Yeah nice try. Dawn Finney.

Question: Is it ok for our song to have two parts like the my first song file?

Extra stuff is okay as long as you still have all that is required, but if it's something like my homework has 30 SongNodes, your TA might be a little annoyed with you. Dawn Finney.

Question:Why do we need to modify SongPhrase?

"You must also create your own riffs in SongPhrase. You can simply type in music, or you can compute your riff � any way you want to do it is fine. Just create at least one phrase (of more than a couple notes) that is interesting and unique," from HW4 Description. That's why. Best get crackin' :P -Dawn Finney

Question: If we are typing in our own riffs in a separate java file, say "myCreatedRiffs.java" or something along those lines, should we copy and paste the contents of that file into SongPhrase, or is it ok to have it separate?

Why would you have two files? Just use one. Is it really so hard to copy and paste? Dawn Finney.

No Dawn, it isn't so hard, that's why I asked. Thanks for the sarcasm though, I really do appreciate it.

Sorry can't really turn it off. Dawn Finney.

Question: Why do I keep getting identifier expected errors whenever I use setNext, setPhrase, or showFromMeOn. I even copied code directly from the book and it still gave me the same error.

I'd probably have to see more to give you a good response. You probably don't have the code within a method, something like main. Dawn Finney.

Question: Dawn in your slides about about weaving (which was very helpful) I see that you reset the list back to its original state before every weave. Do you recommend we do that? is there a why you reason you did that?

No you don't have to reset back every time. I only did it so I could minimize the amount of nodes I had to work with. I did the presentation all within one night so I could get it out before an exam. I was trying to save time. Dawn Finney.

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Homeworks-Spring 2007 last edited on 19 April 2007 at 10:45 pm by c-76-17-114-206.hsd1.ga.comcast.net